I also give other diagrams showing the changing declinations of the brightest stars, those which would naturally be observed, between the years 150 A.D. and 2150 B.C. These have been plotted from the calculations of the authorities I have named.

Fig. 34 deals with the Northern stars. The stars are numbered as follows:—

On Fig. 35, dealing with the Southern stars, the names are given along the curves.

Now supposing that we have our plans; that we have determined the azimuth of the sight lines; and have found the declination of the star observed; we may find more than one star occupying that declination at various dates.

Which of these stars, then, must we consider?

Obviously those most conveniently situated for enabling the time to be estimated during the night, or those which could have been used as warning stars.

The warning stars can be conveniently picked up by using a precessional globe. From it we gather that about 1900, 1400 and 800 B.C. they were as follows for the critical times of the May year, i.e. May, August, November, February:—

For the solstices, that is, June and December, the following stars might be used as warners:—

It is obvious that a star used all the year round for night work will warn the sunrise at some one of the yearly festivals.

When the stars having the same declinations are considered from this point of view, the star actually used, and therefore the date of its use, may generally be gathered. I shall show subsequently that some of the stars in the above lists were actually observed in British as well as in Grecian temples.

CHAPTER XII
ASTRONOMICAL HINTS FOR ARCHÆOLOGISTS—Continued.

I next come to the sun observations.

First we must consider the astronomical differences between the rising of a star and of the sun, by which we generally mean that small part of the sun’s limb first visible.

It is frequently imagined that for determining the exact place of sunrise or sunset in connection with these ancient monuments we have to deal with the sun’s centre, as we should do with the sun half risen. As a matter of fact, we must consider that part of the sun’s limb which first makes its appearance above the horizon; the first glimpse of the upper limb of the sun is in question, say, when the visible limb is 2′ high; and we must carefully take the height of the hills over which it rises into account.

The accompanying diagram will at once show the difference between the rising conditions we have now to consider. It deals with the summer solstice, as being the most precise case, in Lat. 59° N.

At this time the position of the sun, that is of the sun’s centre, as given in the “Nautical Almanac,” is represented by the double circle on the sea horizon.

The azimuth of this position is N. 39° 16′ E. This is the equivalent of the declination of a star, but it will be seen that the real azimuths we want are very different. The dotted circles represent the actual position of the sun with regard to the horizon, the continuous circles the apparent positions caused by the lifting-up effect of refraction. We have the positions in azimuth of the apparent sun as it appears on a sea horizon, and when the horizon is formed by hills up to 1¹⁄₂° in vertical height.

To make this quite clear I give a table which has been computed by Mr. Rolston, of the Solar Physics Observatory, showing azimuths with hills up to 1¹⁄₂° high for lat. 59° N., and 51° N. nearly the latitude of Stonehenge, of the sun’s upper limb for the summer solstice:—

The first important thing we learn from the table is that although at both solstices the azimuths of the rising and setting of the sun’s centre are the same, these azimuths of the upper limb at the summer and winter solstices differ in a high northern latitude by some 5°. The difference arises, of course, from the fact that the limb is some 16′ from the sun’s centre, so that considering the sun’s centre as a star with fixed declination, at rising the limb appears before the centre, and at setting it lags behind it.

It will also be seen that at sunrise hills increase the azimuth from N., and refraction reduces it; while at setting, hills reduce the azimuth from S. and refraction increases it.

This diagram and table should fully explain the variation of azimuth at sunrise caused by the fact that from our present point of view we do not deal with the sun as a star.

To make the foregoing applicable for monuments in all latitudes between Brittany and the Orkneys, I give still another diagram, Fig. 37, also prepared for me by Mr. Rolston which will enable any archæologist to determine approximately, for the present time, the azimuth of sunrise at the summer solstice, without waiting for the 21st of June in any year actually to observe it.

As before stated, I have dealt with the solstice in this chapter because it affords us the most precise case. I hope to be able to deal with the May year sun in the same way later on.

CHAPTER XIII
STENNESS (Lat. 59° N.).

I wrote a good deal in Nature[20] on sun and star temples in 1891, and Mr. Lewis the next year expressed the opinion that the British stone monuments, or some of them, were sun and star temples.

Mr. Magnus Spence, of Deerness, in Orkney, published a pamphlet, “Standing Stones and Maeshowe of Stenness,”[21] in 1894; it is a reprint of an article in the Scottish Review, October, 1893, showing that the stones were set up for solar worship. Mr. Cursiter, F.S.A., of Kirkwall, in a letter to me dated March 15, 1894, a letter suggested by my “Dawn of Astronomy,” which appeared in that year, and in which the articles which had been published in Nature in 1891 had been expanded, directed my attention to the pamphlet.

I began the consideration of the Stenness circles and alignments in 1901, but other pressing calls on my time then caused me to break off the inquiry. Quite recently it occurred to me that a complete study of the Stenness circles might throw light on the question of an earlier Stonehenge, so I have gone over the old papers, plotting the results on the Ordnance map.

Now that the inquiry is as complete as I can make it without spending some time in Orkney with a theodolite, I will begin my reference to other circles besides Stonehenge by stating the conclusions at which I have arrived with regard to the stones of Stenness.

In the first place I may state that although many of the alignments to which Mr. Spence refers in his pamphlet on Maeshowe prove to be very different from those he supposed and drew on the map which accompanies his paper, the main point of his contention is amply confirmed.

I give a copy of the Ordnance map showing the true orientation of these and of other sight-lines I have made out.

The alignments on which Mr. Spence chiefly depended were two, one running from the stone circle past the entrance of Maeshowe to the place of sunrise at Hallowe’en (November 1), another from the same circle by the Barnhouse standing stone to the mid-winter sunrise at the solstice.

Although the map gives these sight-lines, I shall show that they had not the use Mr. Spence attributes to them; but still observations of the sun were provided for on the days in question, and the circles and outstanding stones were undoubtedly set up to guide astronomical observations relating to the different times of the year. Of course, as I have shown elsewhere, such astronomical observations were always associated with religious celebrations of one kind or another, as the astronomer and the priest were one.

I shall not refer to all the sight-lines indicated, but deal only with those which I have without local knowledge been able to test and justify by means of the 25-inch Ordnance map.

Not only does calculation prove the worship of the May and June years, but I think the facts now before us really go to show that in Orkney the May year was the first established, and that the solstitial (June) year came afterwards, and this was one of the chief questions I had in view.

I will begin with the May year. I have already shown, p. 22, that the half-way time between an equinox and a solstice is when the sun’s centre has a declination approximately 16° 20′ N. or S. In Orkney, with the latitude of 59°, assuming a sea horizon, the approximate amplitude of sunrise or sunset is 33° 6′, the corresponding azimuth being 56° 54′.

Now the most interesting and best defined line near this azimuth on the Ordnance map is the one stretching S.E. from the centre of the Stenness circle to the Barnstone, with an azimuth of 57° 15′. The line contains between the two points I have named another stone, the Watchstone, 18¹⁄₂ feet high, in the precise alignment; and from the statements made and measures given it is to be inferred that a still more famous and perforated stone, the “Stone of Odin,” demolished seventy years since, was also in the same line within the extremities named.

If we may accept this we learn something about perforated stones, and can understand most of the folk lore associated with them, and few have more connected with them than the one at Stenness. I suggest that the perforation, which was in this case 5 feet from the ground, was used by the astronomer-priest to view the sunrise in November over the Barnhouse stone in one direction, and the sunset in May over the circle in the other. I hope to be able to return to this question subsequently.

There is another echo of this fundamental line; that joining the Ring of Bookan and the Stones of Via has the same azimuth and doubtless served the same purpose for the May year.

But this line, giving us the May sunset and November sunrise, not the December solstitial sunrise as Mr. Spence shows it, is not the only orientation connected with the May year at the stones of Stenness. The November sunset is provided for by a sight-line from the circle to a stone across the Loch of Stenness with an azimuth of S. 53° 30′ W.

To apply the table, given on p. 120, to the solstitial risings and settings at Stenness, and the sight-lines which I have plotted on the map, it will be seen that the table shows us that the lines marked

are solstitial lines; to get exact agreement with the table the heights of the hills must be found and allowed for.

I have roughly determined this height from the 1-inch map in the case of the Barnstone-Maeshowe alignment. On the N.E. horizon are the Burrien Hills, four miles away, 600 feet high at the sunrise place, gradually ascending to the E., vertical angle = 1° 36′ 30″. The near alignment is on and over the centre of Maeshowe. Colonel Johnston, the Director-General of the Ordnance Survey, has informed me that the true azimuth of this bearing is N. 41° 16′ E., and in all probability it represents the place of sunrise as seen from the Barnstone when Maeshowe was erected. What is most required in Orkney now is that some one with a good 6-inch theodolite should observe the sun’s place of rising and the angular height of the hills at the next summer solstice in order to determine the date of the erection of Maeshowe. Mr. Spence and others made an attempt to determine this value with a sextant in 1899, but not from the Barnstone.

In the absence of this observation we may use the diagram given on p. 121. With the height of hill previously given the sun should rise according to calculation at about the azimuth N. 41° 50′ E.

The difference between the new and old azimuth then, on the assumption that az. N. 41° 16′ E. really represents an observation over Maeshowe, gives us the difference of date.

Treating these figures then as we have done in the case of Stonehenge in Chapter VII, the result is as follows. The Barnhouse-Maeshowe line was established about 700 B.C., when the obliquity had a value of 23° 48′ according to Stockwell’s tables. (Fig. 40.)

I confess the late date does not surprise me. The masonry of Maeshowe differs widely from that of other similar structures in that the sides of the gallery and chamber, instead of being composed of upright stones, are built in regular courses.

I do not believe that the Maeshowe structure was built to observe a winter sunrise twenty days from the solstice, nor can I think it was set up at midsummer by someone who had only dealt with a high sun and a sea horizon, and imagined that the sunrise and sunset points were exactly opposite to each other. It was a priest’s house, and the alignment of the passage to the Barnstone was for the exchange of signals, probably by lights in Maeshowe itself.

The Ordnance maps give no indication of stones, &c., by which the direction of the midsummer setting or the midwinter rising and setting might have been indicated from either the Maeshowe or the Barnstone.

To sum up the solar alignments from the circle.

We have the May sunrise marked by the top of Burrien Hill, from 600 to 700 feet high, Az. 59° 30′.

We have the November sunset marked by a standing stone on the other side of the Loch of Stenness, Az. 53° 30′.

June rising, Line from Barnstone over Maeshowe tumulus.

December rising, tumulus (Az. 41°) on Ward Hill.

December setting, tumulus Onston 36° 30′.

It is not a little remarkable that the summer solstice rising and the winter solstice rising and setting seem to have been provided for at the Stenness circle by alignment on the centres of tumuli, two of them, across the Loch, one the Onston tumulus to the S.W. (Az. 36° 30′), the other tumulus being on Ward Hill to the S.E., Az. 41° (rough measurement).

If the Maeshowe tumulus was a structure erected at the time I have suggested to use the Barnstone for the summer solstice rising; then these two other tumuli, to deal with the winter solstice at Stenness circle, may have been built at the same time. All these provided for a new cult.

There are also tumuli near the line (which cannot be exactly determined because the heights of the hills are unknown) of the summer solstice setting; none was required for the sunrise at this date, as the line passes over the highest point of Hindera fiold, a natural tumulus more than 500 feet high, and on that account a triangulation station.

Another argument in favour of the tumuli being additions to the original design is that the place of the November setting from the Stenness circle is marked, not by a tumulus, but by a standing stone. As this stone, near Deepdale, and the tumulus at Onston are only about 1200 yards apart, the suggestion may be made that under certain unknown conditions and possibly in later times tumuli in some cases replaced stones as collimation marks.

With regard to the clock-star, it is to be feared that the stones in the N.E. quadrant as viewed from the circle which might have given us a clue have been removed. As the latitude of Stenness is N. 59°, some star with a less declination than N. 31° would have been chosen, assuming that the sky-line towards the N. point is not very high.

CHAPTER XIV
THE HURLERS (Lat. 50° 31′ N.)

The sight-lines to which I have drawn attention in relation to the stones of Stenness had to do with the places of sunrise and sunset in the May and Solstitial years. I now pass to another group of circles in which we deal chiefly with the places of star-rise and star-set, some of the stars being used as warners for sunrise at the critical times of the two years in question.

Following the clue given me in the case of the Egyptian temples, such as Luxor, by successive small changes of the axis necessitated by the change in a star’s place due to precession, I began this stellar branch of the inquiry by looking out for this peculiarity in an examination of many maps and plans of circles.

I very soon came across two examples in which the sight-line had been changed in the Egyptian manner. The first is the three circles of the Hurlers, some 5 miles to the north of Liskeard, a plan of which is given in “Prehistoric Stone Monuments of the British Isles: Cornwall,” by W. C. Lukis, Rector of Wath, Yorkshire, published by the Society of Antiquaries, who were so good as to furnish me with a copy, and also some unfolded plans on which sight-lines could be accurately drawn and their azimuths determined. I am anxious to express my obligations to the council and officers of the society for the help thus afforded me.

The three circles are thus referred to by Lukis in the valuable monograph which I have already mentioned.

“On the moor, about a mile to the south of the singular pile of granite slabs, which rest upon and overlap each other, and is vulgarly called the Cheesewring, there are three large circles of granite stones placed in a nearly straight line in a north-north-east, and south-south-west direction, of which the middle one is the largest, being 135 feet in diameter, the north 110 feet, and the south 105 feet.

“The north Circle is 98 feet, and the south 82 feet from the central one. If a line be drawn uniting the centres of the extreme Circles, the centre of the middle ring is found to be 12 feet 6 inches to the west of it.

“These Circles have been greatly injured. The largest consists of 9 erect and 5 prostrate stones; the north Circle has 6 erect and 6 prostrate, and a fragment of a seventh; and the south has 3 erect and 8 prostrate. In Dr. Borlase’s time they were in a slightly better condition. A pen-and-ink sketch made by him, which is extant in one of Dr. Stukeley’s volumes of original drawings, represents the middle Circle as consisting of 7 erect and 10 prostrate stones; the north of 10 erect and 6 prostrate; and the south of 3 erect and 9 prostrate. The stone to the east of that marked C in the plan of the middle Circle is the highest, and is 5 feet 8 inches out of the ground, and appears to have been wantonly mutilated recently. Two of the prostrate stones of the north Circle are 6 feet 6 inches in length.

“About 17 feet south from the centre of the middle Circle there is a prostrate stone 4 feet long and 15 inches wide at one end. It may possibly have been of larger dimensions formerly, and been erected on the spot where it now lies, but as Dr. Borlase has omitted it in his sketch it is probably a displaced stone of the ring.

“If we allow, as before, an average interval of 12 feet between the stones, there will have been about 28 pillars in the north, 26 in the south, and 33 in the middle Circle.

“At a distance of 409 feet westwards from K in the middle Circle there are 2 stones, 7 feet apart, both inclined northwards. One is 4 feet 11 inches in height out of the ground, and overhangs its base 2 feet 7 inches; the other is 5 feet 4 inches high, and overhangs 18 inches.”

I now pass from a general description of the circles to the azimuths of the sight-lines already referred to, so far as they can be determined from the published Ordnance maps.

To investigate them as completely as possible without local observations in the first instance, I begged Colonel Johnston, R.E., C.B., the Director-General of the Ordnance Survey, to send me the 25-inch maps of the site giving the exact azimuth of the side lines. This he obligingly did, and I have to express my great indebtedness to him.

In Fig. 41 I show the sight-lines from the south and north Circles as determined by the stones and barrows marked on the map. The sight-lines on Arcturus are from the centres of the three circles in succession. I shall point out later the significance of the fact that the November alignments are from the south, the solstitial ones from the north Circle.

Of the various sight-lines found, those to which I wish to direct attention in the first instance, and which led me to the others, are approximately, reading the azimuths to the nearest degree,

In a preliminary inquiry in anticipation of the necessary local observations with a theodolite, I assumed hills half a degree high, for the reason given on p. 112. We have the following declinations approximately:—

Here, then, we have declinations to work on, but declinations of what star? To endeavour to answer this question I studied the declinations of the three brightest stars in the northern heavens, having approximately the declinations in question some time or other during the period 0 to 2500 B.C.

Vega is ruled out as its declination was too high. The remaining stars Capella and Arcturus may have been observed so far as the declinations go. For time limits we have:—

Now there is no question as to which of these two stars we have to deal with, for the northern circle is evidently less ancient than the others, for some of the stones are squared and the others are less irregular than those in the S. circle.

This being so, the approximate dates of the use of the three circles at the Hurlers can be derived. They are, with the above assumption:—

The next step was to obtain, by means of a large circular protractor, more accurate readings of the Ordnance Map. This I could do, but the all important question of the angular height of the horizon remained. As it was impossible for me to leave London when the significance of the alignments was made out, I appealed to the authorities of the Royal Cornwall Polytechnic Society for aid in obtaining the necessary angles, and as a result, Captain J. S. Henderson, of Falmouth, an accomplished surveyor, volunteered his aid and shortly sent me the angular heights along some of the alignments, the means of eight readings obtained with a 6-inch theodolite, both verniers and reversed telescopes being employed. Other students of science besides myself will, I am sure, feel their indebtedness for such opportune help.

The combination of the large protractor and theodolite work gives the following final values. The difference between them and the provisional ones given above speaks volumes as to the necessity of a local study of the height of the horizon, a point I believe invariably neglected by archæologists.

FINAL VALUES.

Now before this evidence of star worship, so important if it can be depended on, could be accepted, it was necessary to make a special inquiry as to the existence of similar star observations in other places. Many have been found of which more in the sequel.

The next point which arose was that Arcturus used as a clock-star (p. 108) would serve as a warner for August. This necessitated another inquiry into the chief festivals in Cornwall: among these the August (Harvest) festival is one.

Another point to consider was whether there was any evidence of a local August festival. It happens that the Hurlers are in the parish of St. Cleer, and some of the other Arcturus sight-lines are in that of St. Just. Now, a local festival in old days was often associated with the local Saint. As most of the Cornish Saints are common to Cornwall and Brittany, I looked up the Calendar of the Annuaire of the Institut de France, and found that the days dedicated to SS. Justin and Claire are the 9th and 12th of August. It seems, then, that at the Hurlers it was really a question of a clock-star also used as a warning star for the August festival. I think we have at last, then, run to earth the origin of some of the northerly alignments referred to on pages 36 and 43.

It will have been noted that the last sight-line on Arcturus was marked by a barrow. Captain Henderson inspected it and found it much ruined by explorers, remains of a chamber inside being visible.

In a subsequent visit, in which Captain Henderson was accompanied by Mr. Horton Bolitho, my wife and myself, we not only visited this barrow, but found that the whole hill had been honeycombed to such an extent by mining operations that it was very difficult to discriminate between “investigated” barrows and other heaps and holes, unless the barrow showed the remains of a chamber.

Our examination was not limited to barrows. Captain Henderson had spent a long bleak day in examining and measuring the stones marked on the Ordnance Map, to which I had called his special attention. We went over part of the ground with him, and came to the conclusion that the whole question of the Cornish treatment of “ancient stones” would have to be gone into—an inquiry which Mr. Bolitho is now carrying on.

It must be remembered that any stone or barrow used in the sight-lines we are now considering must have been put up nearly 4,000 years ago, so long ago, in fact, that many of the chief barrows have been reduced to the skeletons of their former selves, the enclosed stone chamber, built of mighty stones, alone remaining.

Cromlechs and standing stones then formed important points in the landscape long before ecclesiastical divisions were thought of, or any attempt was made to indicate the boundaries of private property.

We should expect then to find these ancient monuments freely made use of to mark what we now term “parish boundaries.” This is so. Four parishes have thus used one of the larger cromlechs, and it is more than probable that something beside the denunciation of the cultus lapidum, which we have seen at work in Brittany (p. 39), has been responsible for the many stone crosses in Cornwall. Of some of them near circles I have gathered the astronomical use, while now they “mark the bounds,” as do some of the stone rows in Dartmoor.

I believe that in later times this practice of the Church was followed by those among whom the land was distributed, and this has gone on till at last there are many ancient stones trimmed on one side and bearing initials and so having a modern appearance. The astronomer, and even the archæologist, may regret this practice, but as the habit in Cornwall appears to be for anybody to use the nearest uncrossed and uninitialled stone for a wall or a pigsty, Mr. Bolitho’s inquiry may show that in some cases, at all events, it has been a blessing in disguise, for the stones are still there.

In the case of a long chambered barrow, the top of which nearly touches the horizon, as seen from a circle near it, there is less danger of being misled.

In my notes on the stones of Stenness (Chapter XIII) I pointed out that the chambered Cairns at Onston and Maeshowe suggested that such structures were later variants of the more ancient standing stones. Some barrows at the Hurlers lend further confirmation of this view. I will deal with them first. Of one the data are Az. from N. Circle S. 72° 49′ W., height of horizon 12′ (Capt. Henderson). The resulting declination is S. 11° 5′, the declination of Antares 1720 B.C. But why should Antares be thus singled out? The table on page 117 shows the reason. At the date involved the setting of Antares in the dawn was the warner of the sunrise on May morning, the greatest day in all the year.

Is there any precedent for this use of Antares?

I have already pointed out (p. 108) that Mr. Penrose found the warning stars for May morning at the dates of foundation of the Hecatompedon, and the older Erechtheum, to be the group of the Pleiades rising and Antares setting. As the foundations of the Hecatompedon were built only some few years after the stones of the central circle of the Hurlers were used, we ought to find traces of the observations of the same May-morning stars.

We have, then, now a third term in the astronomical use of stars to herald the sunrise on May morning.

The next barrow to be referred to—it is shown to be a long one on the Ordnance Map—is situated near the top of Caradon Hill, and is visible on the sky-line from the circles. Data: Az. from N. Circle S. 65° E., height of horizon 1° 38′ (Henderson). This corresponds almost exactly with the azimuth of the rise of the sun’s upper limb with declination S. 16° 20′ on the two critical dates in November and February of the May-year (Halloween and Candlemas, see p. 23), so I am inclined to consider it more than a mere coincidence that the azimuths coincide so closely. It, however, may be urged that there are other barrows on Caradon Hill, but judging from the Ordnance Map they seem to be of the round variety used for burials, perhaps a thousand years after the circles were in use, and in my opinion by a different race of men; but this matter must not detain us now, I hope to return to it later.

Still one more barrow and a stone, uncrossed and uninitialled, in the same sight-line, data: Az. from N. circle S. 59° 35′ E. Height of horizon 1° 38′ 23″ (Henderson), resulting declination S. 19° 50′. This was the declination of Sirius 1690 B.C. Why Sirius? The table on p. 117 gives us the answer. Sirius replaced Arcturus as a warning star for the August festival, and we have seen that the last use of Arcturus was connected with the sight-line to the barrow about 1900 B.C.

I pass now from barrows to stones. There is one about which there can be no question. It is a famous Cross, a “Longstone” at which all travellers stop on their way from St. Cleer to the Hurlers. It occupies nearly the same position on the S.W. horizon as does the long tumulus on Caradon Hill in the S.E. quadrant. From the South Circle, and this is important, its Azimuth, S. 64° W., is nearly the same; it marked, and still marks, the sunset point on the critical days of the May year in November and February.

There is another stone marked on the Ordnance Map Az. N. 88° E. from the N. circle. It has been removed, so I may fairly assume that it was really an ancient stone. Captain Henderson’s value for the height of the horizon is 11′ 31″. The table on p. 117 will show that in this direction we have to deal with Betelgeuse as a warner for the summer solstice. The resulting date is 1730 B.C.

It would appear that possibly this is not the only stone dealing with (later) solstitial alignments. Lukis gives two stones on the west side of the circles which on the Ordnance Map are classed as boundary stones: they lie on a boundary beyond all question, but also beyond all question they are as ancient as the stones of the circles themselves. From the N. circle they are almost but not quite in a line, and the azimuth of the south stone is S. 49° W. This is a solstitial azimuth. I think, therefore, that we may accept this as another evidence of the worship of the setting sun at the winter solstice, from the N. circle, and in this we have still further evidence that to the worship of the May year in the south circle was added later one dealing with the solstitial year which was chiefly carried on in the N. circle.

CHAPTER XV
THE DARTMOOR AVENUES

In Chapter XI. I referred to the very numerous alignments of stones in Brittany, and I was allowed by Lieutenant Devoir, of the French Navy, to give some of his theodolite observations of the directions along which the stones had been set up.

The conclusion was that we were really dealing with monuments connected with the worship of the sun of the May year, a year which the recent evidence has shown to have been the first used after the length of the year had been determined; thus replacing the lunar unit of time which was in vogue previously, and the use of which is brought home to us by the reputed ages of Methuselah and other biblical personages, who knew no other measurer of time than the moon.

There was also evidence to the effect that in later times solstitial alignments had been added, so that the idea that we were dealing with astronomically oriented rows of stones was greatly strengthened, not to say established.

So long as the Brittany alignments were things of mystery, their origin, as well as that of the more or less similar monuments in Britain, was variously explained; they were models in stone of armies in battle array, or they represented funeral processions, to mention only two suggestions. I should add that Mr. H. Worth, who has devoted much time to their study, considers that some sepulchral interest attaches to them, though he thinks it may be argued that that was secondary, even as are interments in cathedrals and churches. About burials associated with them, of course, there is no question, for the kistvaens and cairns are there; but my observations suggest that they were added long after the avenues were built, because some cairns block avenues. Perhaps a careful study of the modes of burial adopted may throw light on this point.

The equivalents of the Brittany alignments are not common in Britain; they exist in the greatest number on Dartmoor, whither I went recently to study them. The conditions on high Dartmoor are peculiar; dense blinding mists are common, and, moreover, sometimes come on almost without warning. From its conformation the land is full of streams. There are stones everywhere. What I found, therefore, as had others before me, was that as a consequence of the conditions to which I have referred, directions had been indicated by rows of stones for quite other than ceremonial purposes. Here, then, was another possible origin. It was a matter of great importance to discriminate most carefully between these alignments, and to endeavour to sort them out. My special inquiry, of course, was to see if they, like their apparent equivalents in Brittany, could have had an astronomical origin. The first thing to do, then, was to see which might have been erected for worship or which for practical purposes.

In doing this there is no difficulty in dealing with extremes. Thus one notable line of large flat stones has been claimed by Messrs. R. N. Worth and R. Burnard as a portion of the Great Fosseway (Rowe’s Perambulation, third edition, p. 63); it has been traced for eighteen miles from beyond Hameldon nearly to Tavistock, the stones being about 2 feet thick and the road 10 feet wide.