The conditions to be secured in a lightning-conductor are, firstly, a sharp point projecting above the highest part of the building, and gilded to prevent corrosion; secondly, metallic continuity from the point to the lower end of the conductor; and, thirdly, a good earth-contact. The last can frequently be secured by soldering the conductor to iron water-pipes underground. Where these are not available, a copper plate, two or three feet square, imbedded in clay or other damp earth, will serve the purpose. The method of securing a building which is erected on granite or other foundation affording no good earth-connection, will be referred to in a subsequent biographical sketch.
The controversy of points versus knobs was again revived in London when Franklin was in Paris, and the War of Independence had begun. Franklin was consulted on the subject, the question having arisen in connection with the conductor at the palace. His reply was characteristic.
"As to my writing anything on the subject, which you seem to desire, I think it not necessary, especially as I have nothing to add to what I have already said upon it in a paper read to the committee who ordered the conductors at Purfleet, which paper is printed in the last French edition of my writings.
"I have never entered into any controversy in defence of my philosophical opinions. I leave them to take their chance in the world. If they are right, truth and experience will support them; if wrong, they ought to be refuted and rejected. Disputes are apt to sour one's temper and disturb one's quiet. I have no private interest in the reception of my inventions by the world, having never made, nor proposed to make, the least profit by any of them. The king's changing his pointed conductors for blunt ones is, therefore, a matter of small importance to me. If I had a wish about it, it would be that he had rejected them altogether as ineffectual. For it is only since he thought himself and family safe from the thunder of Heaven, that he dared to use his own thunder in destroying his innocent subjects."
The paper referred to was read before "the committee appointed to consider the erecting conductors to secure the magazines at Purfleet," on August 27, 1772. It described a variety of experiments clearly demonstrating the effect of points in discharging a conductor. This was a committee of the Royal Society, to whom the question had been referred on account of Dr. Wilson's recommendation of a blunt conductor. The committee decided in favour of Franklin's view, and when, in 1777, the question was again raised and again referred to a committee of the Royal Society, the decision of the former committee was confirmed, "conceiving that the experiments and reasons made and alleged to the contrary by Mr. Wilson are inconclusive."
Though Franklin's scientific reputation rests mainly on his electrical researches, he did not leave other branches of science untouched. Besides his work on atmospheric electricity, he devoted a great deal of thought to meteorology, especially to the vortical motion of waterspouts. The Gulf-stream received a share of his attention. His improvements in fireplaces have already been noticed; the cure of smoky chimneys was the subject of a long paper addressed to Dr. Ingenhousz, and of some other letters. One of his experiments on the absorption of radiant energy has been deservedly remembered.
"My experiment was this: I took a number of little square pieces of broad-cloth from a tailor's pattern-card, of various colours. There were black, deep blue, lighter blue, green, purple, red, yellow, white, and other colours or shades of colours. I laid them all out upon the snow in a bright, sun-shiny morning. In a few hours (I cannot now be exact as to the time) the black, being warmed most by the sun, was sunk so low as to be below the stroke of the sun's rays; the dark blue almost as low, the lighter blue not quite so much as the dark, the other colours less as they were lighter; and the quite white remained on the surface of the snow, not having entered it at all.
"What signifies philosophy that does not apply to some use? May we not learn from hence that black clothes are not so fit to wear in a hot, sunny climate or season, as white ones?"
Franklin knew much about electricity, but his knowledge of human nature was deeper still. This appears in all his transactions. His political economy was, perhaps, not always sound, but his judgment of men was seldom at fault.
"Finally, there seem to be but three ways for a nation to acquire wealth. The first is by war, as the Romans did, in plundering their conquered neighbour: this is robbery. The second by commerce, which is generally cheating. The third by agriculture, the only honest way, wherein man receives a real increase of the seed thrown into the ground, in a kind of continual miracle wrought by the hand of God in his favour, as a reward for his innocent life and his virtuous industry."
When Franklin reached London in 1757 he took up his abode with Mrs. Margaret Stevenson, in Craven Street, Strand. For Mrs. Stevenson and her daughter Mary, then a young lady of eighteen, he acquired a sincere affection, which continued throughout their lives. Miss Stevenson spent much of her time with an aunt in the country, and some of Franklin's letters to her respecting the conduct of her "higher education" are among the most interesting of his writings. Miss Stevenson treated him as a father, and consulted him on every question of importance in her life. When she was a widow and Franklin eighty years of age, he urged upon her to come to Philadelphia, for the sake of the better prospects which the new country offered her boys. In coming to England, Franklin brought with him his son William, who entered the Middle Temple, but he left behind his only daughter, Sarah, in charge of her mother. To his wife and daughter he frequently sent presents from London, and his letters to Mrs. Franklin give a pretty full account of all his doings while in England. During his visit he received the honorary degrees of D.C.L. from the University of Oxford, and LL.D. from that of Edinburgh. At Cambridge he was sumptuously entertained. In August, 1762, he started again for America, and reached Philadelphia on November 1, after an absence of five years. His son William had shortly before been appointed Governor of New Jersey. From this time William Franklin became very much the servant of the proprietaries and of the English Government, but no offer of patronage produced any effect on the father.
Franklin's stay in America was of short duration, but while there he was mainly instrumental in quelling an insurrection in Pennsylvania. He made a tour of inspection through the northern colonies in the summer of 1763, to regulate the post-offices. The disorder just referred to in the province caused the governor, as well as the Assembly, to determine on the formation of a militia. A committee, of which Franklin was a member, drew up the necessary bill. The governor claimed the sole power of appointing officers, and required that trials should be by court-martial, some offences being punishable with death. The Assembly refused to agree to these considerations. The ill feeling was increased by the governor insisting on taxing all proprietary lands at the same rate as uncultivated land belonging to other persons, whether the proprietary lands were cultivated or not. The Assembly, before adjourning, expressed an opinion that peace and happiness would not be secured until the government was lodged directly in the Crown. When the Assembly again met, petitions to the king came in from more than three thousand inhabitants. In the mean while the British Ministry had proposed the Stamp Act, which was similar in principle to the English Stamp Act, which requires that all agreements, receipts, bills of exchange, marriage and birth certificates, and all other legal documents should be provided with an inland revenue stamp of a particular value, in order that they might be valid. As soon as the Assembly was convened, it determined to send Franklin to England, to take charge of a petition for a change of government. The merchants subscribed £1100 towards his expenses in a few hours, and in twelve days he was on his journey, being accompanied to the ship, a distance of sixteen miles, by a cavalcade of three hundred of his friends, and in thirty days he reached London. Arrived in London, he at once took up his abode in his old lodgings with Mrs. Stevenson. He was a master of satire, equalled only by Swift, and during the quarrels which preceded the War of Independence, as well as during the war, he made good use of his powers in this respect. Articles appeared in some of the English papers tending to raise an alarm respecting the competition of the colonies with English manufacturers. Franklin's contribution to the discussion was a caricature of the English press writers.
"It is objected by superficial readers, who yet pretend to some knowledge of those countries, that such establishments [manufactories for woollen goods, etc.] are not only improbable, but impossible, for that their sheep have but little wool, not in the whole sufficient for a pair of stockings a year to each inhabitant; that, from the universal dearness of labour among them, the working of iron and other materials, except in a few coarse instances, is impracticable to any advantage.
"Dear sir, do not let us suffer ourselves to be amused with such groundless objections. The very tails of the American sheep are so laden with wool that each has a little car or waggon on four little wheels to support and keep it from trailing on the ground. Would they caulk their ships, would they even litter their horses with wool, if it were not both plenty and cheap? And what signifies the dearness of labour, when an English shilling passes for five and twenty? Their engaging three hundred silk throwsters here in one week for New York was treated as a fable, because, forsooth, they have 'no silk there to throw!' Those who make this objection perhaps do not know that, at the same time, the agents for the King of Spain were at Quebec, to contract for one thousand pieces of cannon to be made there for the fortification of Mexico, and at New York engaging the usual supply of woollen floor-carpets for their West India houses. Other agents from the Emperor of China were at Boston, treating about an exchange of raw silk for wool, to be carried in Chinese junks through the Straits of Magellan.
"And yet all this is as certainly true as the account said to be from Quebec in all the papers of last week, that the inhabitants of Canada are making preparations for a cod and whale fishery this summer in the upper Lakes. Ignorant people may object that the upper Lakes are fresh, and that cod and whales are salt-water fish; but let them know, sir, that cod, like other fish when attacked by their enemies, fly into any water where they can be safest; that whales, when they have a mind to eat cod, pursue them wherever they fly; and that the grand leap of the whale in the chase up the Falls of Niagara is esteemed, by all who have seen it, as one of the finest spectacles in nature."
One of Franklin's chief objects in coming to England was to prevent the passing of Mr. Grenville's bill, previously referred to as the Stamp Act. The colonists urged that they had always been liberal in their votes, whenever money was required by the Crown, and that taxation and representation must, in accordance with the British constitution, go hand-in-hand, so that the English Parliament had no right to raise taxes in America, so long as the colonists were unrepresented in Parliament. "Had Mr. Grenville, instead of that act, applied to the king in Council for such requisitional letters [i.e. requests to the Assemblies for voluntary grants], to be circulated by the Secretary of State, I am sure he would have obtained more money from the colonies by their voluntary grants than he himself expected from the sale of stamps. But he chose compulsion rather than persuasion, and would not receive from their good will what he thought he could obtain without it." The Stamp Act was passed, stamps were printed, distributors were appointed, but the colonists would have nothing to do with the stamps. The distributors were compelled to resign their commissions, and the captains of vessels were forbidden to land the stamped paper. The cost of printing and distributing amounted to £12,000; the whole return was about £1500, from Canada and the West Indies.
The passing of the Stamp Act was soon followed by a change of Ministry, when the question again came before Parliament. Franklin submitted to a long examination before a Committee of the whole House. The feeling prevalent in America respecting the Stamp Act may be inferred from some of his answers.
"31. Q. Do you think the people of America would submit to pay the stamp duty if it was moderated?
"A. No, never, unless compelled by force of arms.
"36. Q. What was the temper of America towards Great Britain before the year 1763?[3]
[3] The date of the Sugar Act.
"A. The best in the world. They submitted willingly to the government of the Crown, and paid, in their courts, obedience to the Acts of Parliament. Numerous as the people are in the several old provinces, they cost you nothing in forts, citadels, garrisons, or armies to keep them in subjection. They were governed by this country at the expense only of a little pen, ink, and paper; they were led by a thread. They had not only a respect, but an affection, for Great Britain—for its laws, its customs and manners, and even a fondness for its fashions, that greatly increased the commerce. Natives of Britain were always treated with particular regard; to be an Old-Englandman was, of itself, a character of some respect, and gave a kind of rank among us.
"37. Q. And what is their temper now?
"A. Oh, very much altered.
"50. Q. Was it an opinion in America before 1763 that the Parliament had no right to lay taxes and duties there?
"A. I never heard any objection to the right of laying duties to regulate commerce; but a right to lay internal taxes was never supposed to be in Parliament, as we are not represented there.
"59. Q. You say the colonies have always submitted to external taxes, and object to the right of Parliament only in laying internal taxes; now, can you show that there is any kind of difference between the two taxes to the colony on which they may be laid?
"A. I think the difference is very great. An external tax is a duty laid on commodities imported; that duty is added to the first cost and other charges on the commodity, and, when it is offered to sale, makes a part of the price. If the people do not like it at that price, they refuse it; they are not obliged to pay it. But an internal tax is forced upon the people without their consent, if not laid by their own representatives. The Stamp Act says we shall have no commerce, make no exchange of property with each other, neither purchase, nor grant, nor recover debts; we shall neither marry nor make our wills, unless we pay such and such sums; and thus it is intended to extort our money from us, or ruin us by the consequences of refusing to pay it.
"61. Q. Don't you think cloth from England absolutely necessary to them?
"A. No, by no means absolutely necessary; with industry and good management they may very well supply themselves with all they want.
"62. Q. Will it not take a long time to establish that manufacture among them? and must they not in the mean while suffer greatly?
"A. I think not. They have made a surprising progress already. And I am of opinion that, before their old clothes are worn out, they will have new ones of their own making.
"84. Q. If the Act is not repealed, what do you think will be the consequence?
"A. A total loss of the respect and affection the people of America bear to this country, and of all the commerce that depends on that respect and affection.
"85. Q. How can the commerce be affected?
"A. You will find that, if the Act is not repealed, they will take a very little of your manufactures in a short time.
"86. Q. Is it in their power to do without them?
"A. I think they may very well do without them.
"87. Q. Is it their interest not to take them?
"A. The goods they take from Britain are either necessaries, mere conveniences, or superfluities. The first, as cloth, etc., with a little industry they can make at home; the second they can do without till they are able to provide them among themselves; and the last, which are much the greatest part, they will strike off immediately. They are mere articles of fashion, purchased and consumed because the fashion in a respected country; but will now be detested and rejected. The people have already struck off, by general agreement, the use of all goods fashionable in mournings, and many thousand pounds' worth are sent back as unsaleable.
"173. Q. What used to be the pride of the Americans?
"A. To indulge in the fashions and manufactures of Great Britain.
"174. Q. What is now their pride?
"A. To wear their old clothes over again till they can make new ones."
The month following Franklin's examination, the repeal of the Stamp Act received the royal assent. Thereupon Franklin sent his wife and daughter new dresses, and a number of other little luxuries (or toilet necessaries).
In 1767 Franklin visited Paris. In the same year his daughter married Mr. Richard Bache. Though Parliament had repealed the Stamp Act, it nevertheless insisted on its right to tax the colonies. The Duty Act was scarcely less objectionable than its predecessor. On Franklin's return from the Continent, he heard of the retaliatory measures of the Boston people, who had assembled in town-meetings, formally resolved to encourage home manufactures, to abandon superfluities, and, after a certain time, to give up the use of some articles of foreign manufacture. These associations afterwards became very general in the colonies, so that in one year the importations by the colonists of New York fell from £482,000 to £74,000, and in Pennsylvania from £432,000 to £119,000.
The effect of the Duty Act was to encourage the Dutch and other nations to smuggle tea and probably other India produce into America. The exclusion from the American markets of tea sent from England placed the East India Company in great difficulties; for while they were unable to meet their bills, they had in stock two million pounds' worth of tea and other goods. The balance of the revenue collected under the Duty Act, after paying salaries, etc., amounted to only £85 for the year, and for this a fleet had to be maintained, to guard the fifteen hundred miles of American coast; while the fall in East India Stock deprived the revenue of £400,000 per annum, which the East India Company would otherwise have paid. At length a licence was granted to the East India Company to carry tea into America, duty free. This, of course, excluded all other merchants from the American tea-trade. A quantity of tea sent by the East India Company to Boston was destroyed by the people. The British Government then blockaded the port. This soon led to open hostilities. Franklin worked hard to effect a reconciliation. He drew up a scheme, setting forth the conditions under which he conceived a reconciliation might be brought about, and discussed it fully with Mr. Daniel Barclay and Dr. Fothergill. This scheme was shown to Lord Howe, and afterwards brought before the Ministry, but was rejected. Other plans were considered, and Franklin offered to pay for the tea which had been destroyed at Boston. All his negotiations were, however, fruitless. At last he addressed a memorial to the Earl of Dartmouth, Secretary of State, complaining of the blockade of Boston, which had then continued for nine months, and had "during every week of its continuance done damage to that town, equal to what was suffered there by the India Company;" and claiming reparation for such injury beyond the value of the tea which had been destroyed. The memorial also complained of the exclusion of the colonists from the Newfoundland fisheries, for which reparation would one day be required. This memorial was returned to Franklin by Mr. Walpole, and Franklin shortly afterwards returned to Philadelphia.
During this visit to England he had lost his wife, who died on December 19, 1774; and his friend Miss Stevenson had married and been left a widow.
In April, 1768, Franklin was appointed Agent for Georgia, in the following year for New Jersey, and in 1770 for Massachusetts, so that he was then the representative in England of four colonies, with an income of £1200 per annum.
In 1771 he spent three weeks at Twyford, with the Bishop of St. Asaph, who remained a fast friend of Franklin's until his death. In 1772 he was nominated by the King of France as Foreign Associate of the Academy of Sciences.
During his negotiations with the British Government Franklin wrote two satirical pieces, setting forth the treatment which the American colonists were receiving. The first was entitled "Rules for Reducing a Great Empire to a Small One," the rules being precisely those which, in Franklin's opinion, had been followed by the British Government in its dealings with America. The other was "An Edict by the King of Prussia," in which the king claimed the right of taxing the British nation; of forbidding English manufacture, and compelling Englishmen to purchase Prussian goods; of transporting prisoners to Britain, and generally of exercising all such controls over the English people as had been claimed over America by various Acts of the English Parliament, on the ground that England was originally colonized by emigrants from Prussia.
Before Franklin reached America, the War of Independence, though not formally declared, had fairly begun. He was appointed a member of the second Continental Congress, and one of a committee of three to confer with General Washington respecting the support and regulation of the Continental Army. This latter office necessitated his spending some time in the camp. On October 3, 1775, he wrote to Priestley:—
Tell our dear good friend, Dr. Price, who sometimes has his doubts and despondencies about our firmness, that America is determined and unanimous; a very few Tories and placemen excepted, who will probably soon export themselves. Britain, at the expense of three millions, has killed a hundred and fifty Yankees this campaign, which is £20,000 a head; and at Bunker's Hill she gained a mile of ground, half of which she lost again by our taking the post on Ploughed Hill. During the same time sixty thousand children have been born in America. From these data his mathematical head will easily calculate the time and expense necessary to kill us all and conquer our whole territory.
In 1776 Franklin, then seventy years old, was appointed one of three Commissioners to visit Canada, in order, if possible, to promote a union between it and the States. Finding that only one Canadian in five hundred could read, and that the state of feeling in Canada was fatal to the success of the Commissioners, they returned, and Franklin suggested that the next Commission sent to Canada should consist of schoolmasters. On the 4th of July Franklin took part in the signing of the Declaration of Independence. When the document was about to be signed, Mr. Hancock remarked, "We must be unanimous; there must be no pulling different ways; we must all hang together." Franklin replied, "Yes, we must indeed all hang together, or most assuredly we shall all hang separately."
In the autumn of 1776 Franklin was unanimously chosen a Special Commissioner to the French Court. He took with him his two grandsons, William Temple Franklin and Benjamin Franklin Bache, and leaving Marcus Hook on October 28, crossed the Atlantic in a sloop of sixteen guns. In Paris he met with an enthusiastic reception. M. de Chaumont placed at his disposal his house at Passy, then about a mile from Paris, but now within the city. Here he resided for nine years, being a constant visitor at the French Court, and certainly one of the most conspicuous figures in Paris. He was obliged to serve in many capacities, and was very much burdened with work. Not only were there his duties as Commissioner at the French Court, but he was also made Admiralty Judge and Financial Agent, so that all the coupons for the payment of interest on the money borrowed for the prosecution of the war, as well as all financial negotiations, either with the French Government or contractors, had to pass through his hands. Perhaps the most unpleasant part of his work was his continued applications to the French Court for monetary advances. The French Government, as is well known, warmly espoused the cause of the Americans, and to the utmost of its ability assisted them with money, material, and men. Franklin was worried a good deal by applications from French officers for introductions to General Washington, that they might obtain employment in the American Army. At last he framed a model letter of recommendation, which may be useful to many in this country in the present day. It was as follows:—
"Sir,
The bearer of this, who is going to America, presses me to give him a letter of recommendation, though I know nothing of him, not even his name. This may seem extraordinary, but I assure you it is not uncommon here. Sometimes, indeed, one unknown person brings another equally unknown, to recommend him; and sometimes they recommend one another! As to this gentleman, I must refer you to himself for his character and merits, with which he is certainly better acquainted than I can possibly be. I recommend him, however, to those civilities which every stranger, of whom one knows no harm, has a right to; and I request you will do him all the good offices and show him all the favour that, on further acquaintance, you shall find him to deserve.
Captain Wickes, of the Refusal, having taken about a hundred British seamen prisoners, Franklin and Silas Deane, one of the other Commissioners, wrote to Lord Stormont, the British ambassador, respecting an exchange. Receiving no answer, they wrote again, and ventured to complain of the treatment which the American prisoners were receiving in the English prisons, and in being compelled to fight against their own countrymen. To this communication Lord Stormont replied:—
The king's ambassador receives no applications from rebels, unless they come to implore his Majesty's mercy.
To this the Commissioners rejoined:—
In answer to a letter, which concerns some of the most material interests of humanity, and of the two nations, Great Britain and the United States of America, now at war, we received the enclosed indecent paper, as coming from your Lordship, which we return for your Lordship's more mature consideration.
At first the British Government, regarding the Americans as rebels, did not treat their prisoners as prisoners of war, but threatened to try them for high treason. Their sufferings in the English prisons were very great. Mr. David Hartley did much to relieve them, and Franklin transmitted money for the purpose. When a treaty had been formed between France and the States, and France had engaged in the war, and when fortune began to turn in favour of the united armies, the American prisoners received better treatment from the English Government, and exchanges took place freely. In April, 1778, Mr. Hartley visited Franklin at Passy, apparently for the purpose of preventing, if possible, the offensive and defensive alliance between America and France. Very many attempts were made to produce a rupture between the French Government and the American Commissioners, but Franklin insisted that no treaty of peace could be made between England and America in which France was not included. In 1779 the other Commissioners were recalled, and Franklin was made Minister Plenipotentiary to the Court of France.
In a letter to Mr. David Hartley, dated February 2, 1780, Franklin showed something of the feelings of the Americans with respect to the English at that time:—
You may have heard that accounts upon oath have been taken in America, by order of Congress, of the British barbarities committed there. It is expected of me to make a school-book of them, and to have thirty-five prints designed here by good artists, and engraved, each expressing one or more of the horrid facts, in order to impress the minds of children and posterity with a deep sense of your bloody and insatiable malice and wickedness. Every kindness I hear of done by an Englishman to an American prisoner makes me resolve not to proceed in the work.
While at Passy, Franklin addressed to the Journal of Paris a paper on an economical project for diminishing the cost of light. The proposal was to utilize the sunlight instead of candles, and thereby save to the city of Paris the sum of 96,075,000 livres per annum. His reputation in Paris is shown by the following quotation from a contemporary writer:—
I do not often speak of Mr. Franklin, because the gazettes tell you enough of him. However, I will say to you that our Parisians are no more sensible in their attentions to him than they were towards Voltaire, of whom they have not spoken since the day following his death. Mr. Franklin is besieged, followed, admired, adored, wherever he shows himself, with a fury, a fanaticism, capable no doubt of flattering him and of doing him honour, but which at the same time proves that we shall never be reasonable, and that the virtues and better qualities of our nation will always be balanced by a levity, an inconsequence, and an enthusiasm too excessive to be durable.
Franklin always advocated free trade, even in time of war. He was of opinion that the merchant, the agriculturist, and the fisherman were benefactors to mankind. He condemned privateering in every form, and endeavoured to bring about an agreement between all the civilized powers against the fitting out of privateers. He held that no merchantmen should be interfered with unless carrying war material. He greatly lamented the horrors of the war, but preferred anything to a dishonourable peace. To Priestley he wrote:—
Perhaps as you grow older you may ... repent of having murdered in mephitic air so many honest, harmless mice, and wish that, to prevent mischief, you had used boys and girls instead of them. In what light we are viewed by superior beings may be gathered from a piece of late West India news, which possibly has not yet reached you. A young angel of distinction, being sent down to this world on some business for the first time, had an old courier-spirit assigned him as a guide. They arrived over the seas of Martinico, in the middle of the long day of obstinate fight between the fleets of Rodney and De Grasse. When, through the clouds of smoke, he saw the fire of the guns, the decks covered with mangled limbs and bodies dead or dying; the ships sinking, burning, or blown into the air; and the quantity of pain, misery, and destruction the crews yet alive were thus with so much eagerness dealing round to one another,—he turned angrily to his guide, and said, 'You blundering blockhead, you are ignorant of your business; you undertook to conduct me to the earth, and you have brought me into hell!' 'No, sir,' says the guide, 'I have made no mistake; this is really the earth, and these are men. Devils never treat one another in this cruel manner; they have more sense and more of what men (vainly) call humanity.'
Franklin maintained that it would be far cheaper for a nation to extend its possessions by purchase from other nations than to pay the cost of war for the sake of conquest.
Two British armies, under General Burgoyne and Lord Cornwallis, having been wholly taken prisoners during the war, at last, after two years' negotiations, a definitive treaty of peace was signed on September 3, 1782, between Great Britain and the United States, Franklin being one of the Commissioners for the latter, and Mr. Hartley for the former. On the same day a treaty of peace between Great Britain and France was signed at Versailles. The United States Treaty was ratified by the king on April 9, and therewith terminated the seven years' War of Independence. Franklin celebrated the surrender of the armies of Burgoyne and Cornwallis by a medal, on which the infant Hercules appears strangling two serpents.
When peace was at length realized, a scheme was proposed for an hereditary knighthood of the order of Cincinnatus, to be bestowed upon the American officers who had distinguished themselves in the war. Franklin condemned the hereditary principle. He pointed out that, in the ninth generation, the "young noble" would be only "one five hundred and twelfth part of the present knight," 1022 men and women being counted among his ancestors, reckoning only from the foundation of the knighthood. "Posterity will have much reason to boast of the noble blood of the then existing set of Chevaliers of Cincinnatus."
On May 2, 1785, Franklin received from Congress permission to return to America. He was then in his eightieth year. On July 12 he left Passy for Havre, whence he crossed to Southampton, and there saw for the last time his old friend, the Bishop of St. Asaph, and his family. He reached his home in Philadelphia early in September, and the day after his arrival he received a congratulatory address from the Assembly of Pennsylvania. In the following month he was elected President of the State, and was twice re-elected to the same office, it being contrary to the constitution for any president to be elected for more than three years in succession.
The following extract from a letter, written most probably to Tom Paine, is worthy of the attention of some writers:—
I have read your manuscript with some attention. By the argument it contains against a particular Providence, though you allow a general Providence, you strike at the foundations of all religion. For without the belief of a Providence that takes cognizance of, guards, and guides, and may favour particular persons, there is no motive to worship a Deity, to fear His displeasure, or to pray for His protection. I will not enter into any discussion of your principles, though you seem to desire it. At present I shall only give you my opinion, that, though your reasonings are subtle, and may prevail with some readers, you will not succeed so as to change the general sentiments of mankind on that subject, and the consequence of printing this piece will be a great deal of odium drawn upon yourself, mischief to you, and no benefit to others. He that spits against the wind spits in his own face.
But were you to succeed, do you imagine any good would be done by it? You yourself may find it easy to live a virtuous life without the assistance afforded by religion; you having a clear perception of the advantages of virtue and the disadvantages of vice, and possessing strength of resolution sufficient to enable you to resist common temptations. But think how great a portion of mankind consists of weak and ignorant men and women, and of inexperienced, inconsiderate youth of both sexes, who have need of the motives of religion to restrain them from vice, to support their virtue, and retain them in the practice of it till it becomes habitual, which is the great point for its security. And perhaps you are indebted to her originally, that is, to your religious education, for the habits of virtue upon which you now justly value yourself. You might easily display your excellent talents of reasoning upon a less hazardous subject, and thereby obtain a rank with our most distinguished authors. For among us it is not necessary, as among the Hottentots, that a youth, to be raised into the company of men, should prove his manhood by beating his mother.
I would advise you, therefore, not to attempt unchaining the tiger, but to burn this piece before it is seen by any other person; whereby you will save yourself a great deal of mortification by the enemies it may raise against you, and perhaps a good deal of regret and repentance. If men are so wicked with religion, what would they be if without it? I intend this letter itself as a proof of my friendship, and therefore add no professions to it; but subscribe simply yours.
During the last few years of his life Franklin suffered from a painful disease, which confined him to his bed and seriously interfered with his literary work, preventing him from completing his biography. During this time he was cared for by his daughter, Mrs. Bache, who resided in the same house with him. He died on April 17, 1790, the immediate cause of death being an affection of the lungs. He was buried beside his wife in the cemetery of Christ Church, Philadelphia, the marble slab upon the grave bearing no other inscription than the name and date of death. In his early days (1728) he had written the following epitaph for himself:—
The Body
of
BENJAMIN FRANKLIN,
Printer,
(like the cover of an old book,
its contents torn out
and stript of its lettering and gilding,)
lies here, food for worms.
but the work shall not be lost,
for it will (as he believed) appear once more
in a new and more elegant edition,
revised and corrected
by
THE AUTHOR.
When the news of his death reached the National Assembly of France, Mirabeau rose and said:—
"Franklin is dead!
"The genius, which gave freedom to America, and scattered torrents of light upon Europe, is returned to the bosom of the Divinity.
"The sage, whom two worlds claim; the man, disputed by the history of the sciences and the history of empires, holds, most undoubtedly, an elevated rank among the human species.
"Political cabinets have but too long notified the death of those who were never great but in their funeral orations; the etiquette of courts has but too long sanctioned hypocritical grief. Nations ought only to mourn for their benefactors; the representatives of free men ought never to recommend any other than the heroes of humanity to their homage.
"The Congress hath ordered a general mourning for one month throughout the fourteen confederated States on account of the death of Franklin; and America hath thus acquitted her tribute of admiration in behalf of one of the fathers of her constitution.
"Would it not be worthy of you, fellow-legislators, to unite yourselves in this religious act, to participate in this homage rendered in the face of the universe to the rights of man, and to the philosopher who has so eminently propagated the conquest of them throughout the world?
"Antiquity would have elevated altars to that mortal who, for the advantage of the human race, embracing both heaven and earth in his vast and extensive mind, knew how to subdue thunder and tyranny.
"Enlightened and free, Europe at least owes its remembrance and its regret to one of the greatest men who has ever served the cause of philosophy and liberty.
"I propose, therefore, that a decree do now pass, enacting that the National Assembly shall wear mourning during three days for Benjamin Franklin."
HENRY CAVENDISH.
It would not be easy to mention two men between whom there was a greater contrast, both in respect of their characters and lives, than that which existed between Benjamin Franklin and the Honourable Henry Cavendish. The former of humble birth, but of great public spirit, possessed social qualities which were on a par with his scientific attainments, and toward the close of his life was more renowned as a statesman than as a philosopher; the latter, a member of one of the most noble families of England, and possessed of wealth far exceeding his own capacity for the enjoyment of it, was known to very few, was intimate with no one, and devoted himself to scientific pursuits rather for the sake of the satisfaction which his results afforded to himself than from any hope that they might be useful to mankind, or from any desire to secure a reputation by making them known, and passed a long life, the most uneventful that can be imagined.
Though the records of his family may be traced to the Norman Conquest, the famous Elizabeth Hardwicke, the foundress of two ducal families and the builder of Hardwicke Hall and of Chatsworth as it was before the erection of the present mansion, was the most remarkable person in the genealogy. Her second son, William, was raised to the peerage by James I., thus becoming Baron Cavendish, and was subsequently created first Earl of Devonshire by the same monarch. His great-grandson, the fourth earl, was created first Duke of Devonshire by William III., to whom he had rendered valuable services. He was succeeded by his eldest son in 1707, and the third son of the second duke was Lord Charles Cavendish, the father of Henry and Frederick, of whom Henry was the elder, having been born at Nice, October 13, 1731. His mother died when he was two years old, and very little indeed is known respecting his early life. In 1742 he entered Dr. Newcome's school at Hackney, where he remained until he entered Peterhouse, in 1749. He remained at Cambridge until February, 1753, when he left the university without taking his degree, objecting, most probably, to the religious tests which were then required of all graduates. In this respect his brother Frederick followed his example. On leaving Cambridge Cavendish appears to have resided with his father in Marlborough Street, and to have occasionally assisted him in his scientific experiments, but the investigations of the son soon eclipsed those of the father. It is said that the rooms allotted to Henry Cavendish "were a set of stables, fitted up for his accommodation," and here he carried out many of his experiments, including all those electrical investigations in which he forestalled so much of the work of the present century.
During his father's life, or, at any rate, till within a few years of its close, Henry Cavendish appears to have enjoyed a very narrow income. He frequently dined at the Royal Society Club, and on these occasions would come provided with the five shillings to be paid for the dinner, but no more. Upon his father's death, which took place in 1783, when Henry was more than fifty years of age, his circumstances were very much changed, but it seems that the greater part of his wealth was left him by an uncle who had been an Indian officer, and this legacy may have come into his possession before his father's death. He appears to have been very liberal when it was suggested to him that his assistance would be of service, but it never occurred to him to offer a contribution towards any scientific or public undertaking, and though at the time of his death he is said to have had more money in the funds than any other person in the country, besides a balance of £50,000 on his current account at his bank, and various other property, he bequeathed none to scientific societies or similar institutions. Throughout the latter part of his life he seems to have been quite careless about money, and to have been satisfied if he could only avoid the trouble of attending to his own financial affairs. Hence he would allow enormous sums to accumulate at his banker's, and on one occasion, being present at a christening, and hearing that it was customary for guests to give something to the nurse, he drew from his pocket a handful of guineas, and handed them to her without counting them. After his father's death, Cavendish resided in his own house on Clapham Common. Here a few rooms at the top of the house were made habitable; the rest were filled with apparatus of all descriptions, among which the most numerous examples were thermometers of every kind. He seldom entertained visitors, but when, on rare occasions, a guest had to be entertained, the repast invariably consisted of a leg of mutton. His extreme shyness caused him to dislike all kinds of company, and he had a special aversion to being addressed by a stranger. On one occasion, at a reception given by Sir Joseph Banks, Dr. Ingenhousz introduced to him a distinguished Austrian philosopher, who professed that his main object in coming to England was to obtain a sight of so distinguished a man. Cavendish listened with his gaze fixed on the floor; then, observing a gap in the crowd, he made a rush to the door, nor did he pause till he had reached his carriage. His aversion to women was still greater; his orders for the day he would write out and leave at a stated time on the hall-table, where his house-keeper, at another stated time, would find them. Servants were allowed access to the portion of the house which he occupied only at fixed times when he was away; and having once met a servant on the stairs, a back staircase was immediately erected. His regular walk was down Nightingale Lane to Wandsworth Common, and home by another route. On one occasion, as he was crossing a stile, he saw that he was watched, and thenceforth he took his walks in the evening, but never along the same road. There were only two occasions on which it is recorded that scientific men were admitted to Cavendish's laboratory. The first was in 1775, when Hunter, Priestley, Romayne, Lane, and Nairne were invited to see the experiments with the artificial torpedo. The second was when his experiment on the formation of nitric acid by electric sparks in air had been unsuccessfully attempted by Van Marum, Lavoisier, and Monge, and he "thought it right to take some measures to authenticate the truth of it."
Besides his house at Clapham, Cavendish occupied (by his instruments) a house in Bloomsbury, near the British Museum, while a "mansion" in Dean Street, Soho, was set apart as a library. To this library a number of persons were admitted, who could take out the books on depositing a receipt for them. Cavendish was perfectly methodical in all his actions, and whenever he borrowed one of his own books he duly left the receipt in its place. The only relief to his solitary life was afforded by the meetings of the Royal Society, of which he was elected a Fellow in 1760; by the occasional receptions at the residence of Sir Joseph Banks, P.R.S.; and by his not infrequent dinners with the Royal Society Club at the Crown and Anchor; and he may sometimes have joined the social gatherings of another club which met at the Cat and Bagpipes, in Downing Street. It was to his visits to the Royal Society Club that we are indebted for the only portrait that exists of him. Alexander, the draughtsman to the China Embassy, was bent upon procuring a portrait of Cavendish, and induced a friend to invite him to the club dinner, "where he could easily succeed, by taking his seat near the end of the table, from whence he could sketch the peculiar great-coat of a greyish-green colour, and the remarkable three-cornered hat, invariably worn by Cavendish, and obtain, unobserved, such an outline of the face as, when inserted between the hat and coat, would make, he was quite sure, a full-length portrait that no one could mistake. It was so contrived, and every one who saw it recognized it at once." Another incident is recorded of the Royal Society Club which, perhaps, reflects as much credit upon Cavendish as upon the Society. "One evening we observed a very pretty girl looking out from an upper window on the opposite side of the street, watching the philosophers at dinner. She attracted notice, and one by one we got up and mustered round the window to admire the fair one. Cavendish, who thought we were looking at the moon, hustled up to us in his odd way, and when he saw the real object of our study, turned away with intense disgust, and grunted out, 'Pshaw!'"
In the spring and autumn of 1785, 1786, 1787, and 1793, Cavendish made tours through most of the southern, midland, and western counties, and reached as far north as Whitby. The most memorable of these journeys was that undertaken in 1785, since during its course he visited James Watt at the Soho Works, and manifested great interest in Watt's inventions. This was only two years after the great controversy as to the discovery of the composition of water, but the meeting of the philosophers was of the most friendly character. On all these journeys considerable attention was paid to the geology of the country.
Allusion has already been made to the two committees of the Royal Society to which the questions of the lightning-conductors at Purfleet, and of points versus knobs for the terminals of conductors, were referred. Cavendish served on each of these committees, and supported Franklin's view against the recommendation of Mr. Wilson. On the first committee he probably came into personal communication with Franklin himself.
Cavendish's life consisted almost entirely of his philosophical experiments. In other respects it was nearly without incident. He appears to have been so constituted that he must subject everything to accurate measurement. He rarely made experiments which were not quantitative; and he may be regarded as the founder of "quantitative philosophy." The labour which he expended over some of his measurements must have been very great, and the accuracy of many of his results is marvellous considering the appliances he had at disposal. When he had satisfied himself with the result of an experiment, he wrote out a full account and preserved it, but very seldom gave it to the public, and when he did publish accounts of any of his investigations it was usually a long time after the experiments had been completed. One of the consequences of his reluctance to publish anything was the long controversy on the discovery of the composition of water, which was revived many years afterwards by Arago's éloge on James Watt; but a much more serious result was the loss to the world for so many years of discoveries and measurements which had to be made over again by Faraday, Kohlrausch, and others. The papers he published appeared in the Philosophical Transactions of the Royal Society, to which he began to communicate them in 1766. On March 25, 1803, he was elected one of the eight Foreign Associates of the Institute of France. His éloge was pronounced by Cuvier, in 1812, who said, "His demeanour and the modest tone of his writings procured him the uncommon distinction of never having his repose disturbed either by jealousy or by criticism." Dr. Wilson says, "He was almost passionless. All that needed for its apprehension more than the pure intellect, or required the exercise of fancy, imagination, affection, or faith, was distasteful to Cavendish. An intellectual head thinking, a pair of wonderfully acute eyes observing, and a pair of very skilful hands experimenting or recording, are all that I realize in reading his memorials." He appeared to have no eye for beauty; he cared nothing for natural scenery, and his apparatus, provided it were efficient, might be clumsy in appearance and of the cheapest materials; but he was extremely particular about accuracy of construction in all essential details. He reminds us of one of our foremost men of science, who, when his attention was directed to the beautiful lantern tower of a cathedral, behind which the full moon was shining, remarked, "I see form and colour, but I don't know what you mean by beauty."
The accounts of Cavendish's death differ to some extent in their details, but otherwise are very similar. It appears that he requested his servant, "as he had something particular to engage his thoughts, and did not wish to be disturbed by any one," to leave him and not to return until a certain hour. When the servant came back, at the time appointed, he found his master dead. This was on February 24, 1810, after an illness of only two or three days.
It is mainly on account of his researches in electricity that the biography of Cavendish finds a place in this volume. These investigations took place between the years 1760 and 1783, and, as already stated, were all conducted in the stables attached to his father's house in Marlborough Street. It was by these experiments that electricity was first brought within the domain of measurement, and many of the numerical results obtained far exceeded in accuracy those of any other observer until the instruments of Sir W. Thomson rendered many electrical measurements a comparatively easy matter. The near agreement of Cavendish's results with those of the best modern electricians has made them a perpetual monument to the genius of their author. It was at the request of Sir W. Thomson, Mr. Charles Tomlinson, and others, that Cavendish's electrical researches might be given to the public, that the Duke of Devonshire, in 1874, entrusted the manuscripts to the care of the late Professor Clerk Maxwell. They had previously been in the hands of Sir William Snow Harris, who reported upon them, but after his death, in 1867, the report could not be found. The papers, with an introduction and a number of very valuable notes by the editor, were published by the Cambridge University Press, just before the death of Clerk Maxwell, in 1879. Sir W. Thomson quotes the following illustration of the accuracy of Cavendish's work:—"I find already that the capacity of a disc was determined experimentally by Cavendish as 1/1·57 of that of a sphere of the same radius. Now we have capacity of disc = (2/π)a = a/1·571!"
Cavendish adopted Franklin's theory of electricity, treating it as an incompressible fluid pervading all bodies, and admitting of displacement only in a closed circuit, unless, indeed, the disturbance might extend to infinity. This fluid he supposed, with Franklin, to be self-repulsive, but to attract matter, while matter devoid of electricity, and therefore in the highest possible condition of negative electrification, he supposed, with Æpinus, to be, like electricity, self-repulsive. One of Cavendish's earliest experiments was the determination of the precise law according to which electrical action varies with the distance between the charges. Franklin had shown that there was no sensible amount of electricity on the interior of a deep hollow vessel, however its exterior surface might be charged. Cavendish mounted a sphere of 12·1 inches in diameter, so that it could be completely enclosed (except where its insulating support passed through) within two hemispheres of 13·3 inches diameter, which were carried by hinged frames, and could thus be allowed to close completely over the sphere, or opened and removed altogether from its neighbourhood. A piece of wire passed through one of the hemispheres so as to touch the inner sphere, but could be removed at pleasure by means of a silk string. The hemispheres being closed with the globe within them, and the wire inserted so as to make communication between the inner and outer spheres, the whole apparatus was electrified by a wire from a charged Leyden jar. This wire was then removed by means of a silken string and "the same motion of the hand which drew away the wire by which the hemispheres were electrified, immediately after that was done, drew out the wire which made the communication between the hemispheres and the inner globe, and, immediately after that was drawn out, separated the hemispheres from each other," and applied the electrometer to the inner globe. "It was also contrived so that the electricity of the hemispheres and of the wire by which they were electrified was discharged as soon as they were separated from each other.... The inner globe and hemispheres were also both coated with tinfoil to make them the more perfect conductors of electricity." The electrometer consisted of a pair of pith-balls; but, though the experiment was several times repeated, they shewed no signs of electrification. From this it was clear that, as there could have been no communication between the globe and hemispheres when the connecting wire was withdrawn, there must have been no electrification on the globe while the hemispheres, though themselves highly charged, surrounded it. To test the delicacy of the experiment, a charge was given to the globe less than one-sixtieth of that previously given to the hemispheres, and this was readily detected by the electrometer. From the result Cavendish inferred that there is no reason to think the inner globe to be at all charged during the experiment. "Hence it follows that the electric attraction and repulsion must be inversely as the square of the distance, and that, when a globe is positively electrified, the redundant fluid in it is lodged entirely on its surface." This conclusion Cavendish showed to be a mathematical consequence of the absence of electrification from the inner sphere; for, were the law otherwise, the inner sphere must be electrified positively or negatively, according as the inverse power were higher or lower than the second, and that the accuracy of the experiment showed the law must lie between the 2 1/50 and the 1 49/50 power of the distance. With his torsion-balance, Coulomb obtained the same law, but Cavendish's method is much easier to carry out, and admits of much greater accuracy than that of Coulomb. Cavendish's experiment was repeated by Dr. MacAlister, under the superintendence of Clerk Maxwell, in the Cavendish Laboratory, the absence of electrification being tested by Thomson's quadrant electrometer, and it was shown that the deviation from the law of inverse squares could not exceed one in 72,000.
The distinction between electrical charge or quantity of electricity and "degree of electrification" was first clearly made by Cavendish. The latter phrase was subsequently replaced by intensity, but electric intensity is now used in another sense. Cavendish's phrase, degree of electrification, corresponds precisely with our notion of electric potential, and is measured by the work done on a unit of electricity by the electric forces in removing it from the point in question to the earth or to infinity. Along with this notion Cavendish introduced the further conception of the amount of electricity required to raise a conductor to a given degree of electrification, that is, the capacity of the conductor. In modern language, the capacity of a conductor is defined as "the number of units of electricity required to raise it to unit potential;" and this definition is in precise accordance with the notion of Cavendish, who may be regarded as the founder of the mathematical theory of electricity. Finding that the capacities of similar conductors are proportional to their linear dimensions, he adopted a sphere of one inch diameter as the unit of capacity, and when he speaks of a capacity of so many "inches of electricity," he means a capacity so many times that of his one-inch sphere, or equal to that of a sphere whose diameter is so many inches. The modern unit of capacity in the electro-static system is that of a sphere of one centimetre radius, and the capacity of any sphere is numerically equal to its radius expressed in centimetres. Cavendish determined the capacities of nearly all the pieces of apparatus he employed. For this purpose he prepared plates of glass, coated on each side with circles of tinfoil, and arranged in three sets of three, each plate of a set having the same capacity, but each set having three times the capacity of the preceding. There was also a tenth plate, having a capacity equal to the whole of the largest set. The capacity of the ten plates was thus sixty-six times that of one of the smallest set. With these as standards of comparison, he measured the capacities of his other apparatus, and, when possible, modified his conductors so as to make them equal to one of his standards. His large Leyden battery he found to have a capacity of about 321,000 "inches of electricity," so that it was equivalent to a sphere more than five miles in diameter. One of his instruments employed in the measurement of capacities was a "trial plate," consisting of a sheet of metal, with a second sheet which could be made to slide upon it and to lie entirely on the top of the larger plate, or to rest with any portion of its area extending over the edge of the former. This was a conductor whose capacity could be varied at will within certain limits. Finding the capacity of two plates of tinfoil on glass much greater than his calculations led him to expect, Cavendish compared them with two equal plates having air between, and found their capacity very much to exceed that of the air condenser. The same was the case, though in a less degree, with condensers having shellac or bee's-wax for their dielectrics, and thus Cavendish not only discovered the property to which Faraday afterwards gave the name of "specific inductive capacity," but determined its measure in these dielectrics. He also discovered that the apparent capacity of a Leyden jar increases at first for some time after it has been charged—a phenomenon connected with the so-called residual charge of the Leyden jar. Another feature on which he laid some stress, and which was brought to his notice by the comparison of his coated panes, was the creeping of electricity over the surface of the glass beyond the edge of the tinfoil, which had the same effect on the capacity as an increase in the dimensions of the tinfoil. The electricity appeared to spread to a distance of 0·07 inch all round the tinfoil on glass plates whose thickness was 0·21 inch, and 0·09 inch in the case of plates 0·08 inch thick.
His paper on the torpedo was read before the Royal Society in 1776. The experiments were undertaken in order to determine whether the phenomena observed by Mr. John Walsh in connection with the torpedo could be so far imitated by electricity as to justify the conclusion that the shock of the torpedo is an electric discharge. For this purpose Cavendish constructed a wooden torpedo with electrical organs, consisting of a pewter plate on each side, covered with leather. The plates were connected with a charged Leyden battery, by means of wires carried in glass tubes, and thus the battery was discharged through the water in which the torpedo was immersed, and which was rendered of about the same degree of saltness as the sea. Cavendish compared the shock given through the water with that given by the model fish in air, and found the difference much greater than in the case of the real torpedo, but, by increasing the capacity of the battery and diminishing the potential to which it was charged, this discrepancy was diminished, and it was found to be very much less in the case of a second model having a leather, instead of a wooden, body, so that the body of the fish itself offered less resistance to the discharge. One of the chief difficulties lay in the fact that no one had succeeded in obtaining a visible spark from the discharge of the torpedo, which will not pass through the smallest thickness of air. Cavendish accounted for this by supposing the quantity of electricity discharged to be very great, and its potential very small, and showed that the more the charge was increased and the potential diminished in his model, the more closely did it imitate the behaviour of the torpedo.
But the main interest in this paper lies in the indications which it gives that Cavendish was aware of the laws which regulate the flow of electricity through multiple conductors, and in the comparisons of electrical resistance which are introduced. It had been formerly believed that electricity would always select the shortest or best path, and that the whole of the discharge would take place along that route. Franklin seems to have assumed this in the passage quoted[4] respecting the discharge of the lightning down the uninsulated conductor instead of through the building. The truth, however, is that, when a number of paths are open to an electric current, it will divide itself between them in the inverse ratios of their resistances, or directly as their conductivities, so that, however great the resistance of one of the conductors, some portion, though it may be a very small fraction, of the discharge will take place through it. But this law does not hold in the case of insulators like the air, through which electricity passes only by disruptive discharges, and which completely prevent its passage unless the electro-motive force is sufficient to break through their substance. In the case of the lightning-conductor, however, its resistance is generally so small in comparison with that of the building it is used to protect, that Franklin's conclusion is practically correct.