It is evident that, in every instance given of losing hazards, if ball 3 be substituted for the pocket the stroke will be converted from a hazard to a cannon; indeed, if that ball lie on any part of the path of ball 1 after impact or within the distance of a radius (1¹⁄₃₂ in.) on either side of the path, a cannon must result. Hence the examples for losing hazards are equally available for practice cannons, the eye-training for the requisite angle being the same. The cannon is in fact easier than the hazard, the target being nearly equal to the width of two balls, as fig. 5 shows; 1 played on 2 may just touch 3 to the left, when it would occupy the position 1′, or it may just touch the other side as shown, 1″. The width of this target varies with the distance between balls 2 and 3; at greatest it may be taken as double the size of a ball, or 4⅛ in. The pocket on the other hand is usually 3⅝ in. at the fall, the target it presents being under the most advantageous circumstances somewhat larger; on the other hand, when it is blind the target is reduced.

A few cannons useful for practice, which if properly played result in gathering the balls, that is in leaving the three balls together, or so placing them that another stroke is left, are shown in the accompanying diagrams. In every case when indication is desirable the path of ball 1 is marked by a thin line; that of ball 2 by a dotted line; and that of ball 3 by a line consisting of a dash and dot alternately. In some cases the positions of the balls after the stroke are indicated thus:—1′, 2′, 3′; 1′ being the position which 1 has taken, and so on; in other cases this is not done because the situations are somewhat indeterminate, and also when the balls are but slightly moved the diagram would be confused and needlessly complicated.

The cannon shown in Diagram XI. is not merely an excellent plain stroke for practice, but the position is not infrequently met with or played for in a game, and is of a type which will repay close attention. As in all other cases, the measurements are merely approximate, and it is evident that a great variety of similar cannons can be set up simply by varying the position of ball 2. For ball 3 is supposed to be on the spot, and ball 1 in hand, so that a slight change in the position of ball 2, either up or down the table or in its distance from the side cushion, merely entails a corresponding move of ball 1, so that the cannon on ball 3 may always be played a soft half-ball. In the present instance, ball 2 is 18 in. from cushion 6, and 6½ in. above the central transverse line of the table. If ball 1 be placed a little to the left of the baulk centre, say from 1 to 2 in., and played half-ball, so as to do little more than reach ball 3, and cannon on its right side, ball 2 will be brought towards the spot from which ball 3 has not been far removed. The balls may not improbably be left in the positions 1′, 2′, 3′, in which case there is an excellent opening; but it must not be expected that in every instance fortune will be equally favourable. Still, unless the stroke is very badly played, the three balls will be left not far from each other, and at the top of the table, and that is a sufficient recommendation. The stroke, when correctly set up, simply requires a true half-ball plain stroke, with attention to strength. If ball 3 is sometimes hit on one side, sometimes on the other, and occasionally missed altogether, the inference is that accuracy in the half-ball stroke is wanting, and it is well to try and recover that by the methods previously recommended; when confidence is restored, then pay particular attention to the strength. Do not be satisfied till ball 3 is displaced from the spot not more than a few inches, say under six. Hence, in this class of cannons, which, like all other strokes, should, whenever possible, be practised under professional supervision, the first thing to do is to place ball 1 correctly for the half-ball angle; the next is to strike 2 precisely half-ball; and the last is to regulate the strength so that ball 1 shall strike ball 2 very gently. These remarks are to some extent general, and may be usefully applied, at the reader’s discretion, to many strokes.

Diagram XII. shows a variation of the stroke just described; ball 2 is still 18 in. from the left side cushion, but is 3 in. below the central transverse line. There is, it is clear, a losing hazard into the left middle pocket from about the right corner of the Ｄ; but it is a better game in this position to place ball 1 2½ to 2¾ in. left of the baulk centre, and play the half-ball cannon. If ball 2 were further from the side cushion, the losing hazard would become the better stroke, and this example may be considered as almost the limit at which the cannon is to be preferred. The balls will approximately follow the paths indicated, and their positions after the stroke may be about 1′, 2′, 3′, a fair chance remaining for continuing the break; and if, as will often happen, ball 1, placed a little wider or played a little finer, should strike ball 3 on the other side, i.e. on the side next the left top pocket, then ball 3 is driven towards the right top pocket, leaving a hazard (a winner for preference) into it, ball 2 is left, as before, near the spot, and the situation is still eminently favourable. If played a great number of times, some unfortunate results will occasionally happen; the three balls may be left in a line, all nearly touching the top cushion, and ball 1 between 2 and 3; even then a way may be found out of the difficulty, but at present the plain cannon is being considered, and it is difficult to set up on the table a better practice stroke.

The cannon shown in Diagram XIII., though apparently a little different, is, in reality, played precisely like the others; the results, too, are in a way the same, for the three balls are gathered at the top of the table. The main difference is that, the cannon being made off the top cushion, ball 1 is generally left above ball 3—a situation not so favourable as when ball 1 is below the other two balls. It often happens, however, that ball 2 is so left that a losing hazard from it into the left top pocket can be made, and the break may be thus continued. The further it is desired to bring ball 2 towards the left top pocket, the more towards baulk centre should ball 1 be placed; and the nearer to the spot it may be wished to leave it, the finer should the stroke be set. One advantage of practising this stroke is that confidence is acquired in making the cannon from the cushion, which is in this instance greatly preferable to playing a forcing stroke direct, though many persons, thinking of the cannon alone, would erroneously select the latter mode of play. A substantial gain is made when the player has recognised that the stroke is almost exactly like the two just described, and that the top cushion may, save in a small extra allowance of strength, be completely ignored.

On Diagram XIV. two cannons are shown; to that marked A special attention is invited. The position, or a similar one, often occurs, and is as often incorrectly played by amateurs, when balls 2 and 3 are on the table, and 1 in hand. Thinking solely of making the cannon, the player usually spots 1 towards the right of the baulk for a half-ball stroke. Result, a cannon and separation of the balls, 2 being doubled towards baulk, 3 carried up the table and not improbably lodged in safety under cushion 6.

Place ball 2, 14 in. from cushion 5, 30 in. below the left middle pocket.

Ball 3, 11 in. from cushion 5, 17 in. below the left middle pocket.

Ball 1, 9 in. to the left of baulk centre. Play a gentle stroke on 2 so as to double it from the cushion to 3 and with strength sufficient for ball 1 to reach 3. The three balls will be left close together and not far from the left middle pocket. Care must be taken to prevent the balls being left in one straight line, and also to avoid a kiss between balls 1 and 2 before the cannon.

Example B, though not of so common occurrence as A, is also an excellent practice stroke.

Ball 1, 5½ in. from cushion 3, 21½ in. from the bottom cushion.

Ball 2, 4 in. from cushion 3, 33 in. from the bottom cushion.

Ball 3, in front of the left top pocket, 3 or 4 in. from it. Play a centre ball stroke, about half-ball on 2, with strength to carry 1 to 3—say a free No. 1. Ball 2 will double from cushion 3 and join 1 and 3 near the left top pocket.

In this stroke accidents may happen, and if it be missed by a hair’s breadth the adversary will rejoice. Ball 3 may be cannoned into the pocket and ball 2 may also go in; but, if played often, the result will generally be satisfactory and the stroke is therefore a fairly sound one. If ball 3 were the red, it would be prudent to play so as to leave ball 2 somewhat behind and thus reduce the danger of losing it in the pocket. A little consideration will show that the varieties of this stroke are numerous, and that by means of some of them the three balls may be brought to the top of the table.

The strokes shown in Diagram XV. exemplify that most useful class of cannons in which the velocity of ball 1, struck often with considerable force, is almost wholly transmitted to ball 2, and 1 retains little more than is required to reach 3. This is achieved in the first place by playing as full as the cannon will admit of on 2, and next by a peculiar use of the cue, which the French term arrêté because it is grasped and not permitted to follow the ball more than an inch or two after delivery. The stroke is a stab, and its intensity can be varied by raising the butt of the cue. The point of ball 1 to be struck is, as before, the centre, but delivery instead of being horizontal is at a smaller or greater angle with the surface of the table. The stroke is made as though the striker desired to stab the ball through its centre to the table. It springs away with more life than can be communicated by a horizontal stroke, and parts with that life on impact with 2 more readily, and therefore expires or comes to rest on reaching 3 with greater certainty. The stab is not required in every case, but where ball 2 has a long path to travel and ball 3 is at a right angle from 2 or less, it cannot be dispensed with. Classified as a stroke, it may be placed between the horizontal centre and the screw, which will be described in the next chapter, whereby ball 1 is made to return towards the point of the cue after impact with 2.

A simple form of these cannons is shown at A on this diagram. No measurements are required, as the position is perfectly simple and equally good for practice when varied according to pleasure. It can be conveniently played when ball 3 is on the pyramid spot, ball 2 about 6 in. from it and rather nearer the player, ball 1 being between the player and 2 near the latter as shown. Play ball 1 nearly full on 2 with strength sufficient to cause its return from the cushion to 3, which 1 should reach but scarcely move. When played as shown across the table the stroke is always a gentle one, and when the balls are close to the cushion from which 2 has to return it must be played very softly indeed. The usual faults made in playing are that 2 is struck too hard and too fine, the result being that the three balls separate instead of coming together.

For B, a pretty little stroke useful in turning the corner at the left top pocket, the following measurements will help in placing the balls, which can however be set up from the diagram with sufficient accuracy.

Ball 1, 5½ in. from cushion 6, 22½ in. from the top cushion.

Ball 2, 3½ in. (full) from cushion 6, 16½ in. from the top cushion.

Ball 3, 8½ in. from cushion 6, 13 in. from the top cushion.

Play a gentle stroke on 2 from ¾ to ½ to the right so as just to reach 3; 2 will return from side and top cushions, and the three balls will be left together. It is evident that this stroke may be adapted to any corner of the table, an exercise which may be left to the student.

Example C.

Ball 2, 19 in. from cushion 6, 16½ in. from the top cushion; ball 3 on the spot; ball 1, 18 in. from cushion 6 and 12 in. from the top cushion.

Play a little less than full on 2 with strength to bring it back from the bottom cushion to the neighbourhood of the spot; ball 1 to travel to 3, which it moves slowly towards the right top corner pocket.

This stroke as exhibited at C is not very difficult, though some moderate execution is required, and an intelligent application of the stab will give more perfect control of the balls. As ball 3 is placed further from 2 and nearer the top cushion, so does the stroke require greater skill and judgment, the stab then becoming more necessary, as the energy or life of ball 1 must expire about the moment it reaches 3, otherwise the success of the stroke is much endangered.

Diagram XVI. shows a position of the balls which at first sight is apt to be regarded with dissatisfaction by the player.

Ball 2 is too near cushion 2 and too far from the right top pocket for a certain losing hazard; say 28 or 29 in. from top cushion and 5½ in. from the side.

Ball 3 is 3 in. from cushion 6 and 12 in. above the middle pocket.

Ball 1 is in the central line of the table, from 9 to 13 in. below the pyramid spot.

Play No. 1 strength finer than half-ball on 2, which strikes cushion 2 and travels towards ball 3; ball 1 makes the cannon off cushions 2 and 1, and sometimes off cushion 6 as well.

The danger of this stroke is that balls 1 and 2 may kiss just before ball 3 is reached, the result being disappointment for the player and a good opening for the adversary. In the modern game, however, a man should look for success to skill and enterprise which, though not without risk, lead to rapid scoring, rather than to tactics of obstruction, so dear to the heart of respectable mediocrity. The results of this stroke will be found to vary considerably. Sometimes ball 3 will be placed over the left middle pocket with a winning or losing hazard for next stroke. Again, if the cannon is made on the right side of ball 3, ball 1 will travel below the pocket, and the next stroke will probably be another cannon. It is clear that this type of stroke can be modified at will; ball 1 may remain fixed whilst ball 3 is moved up the left side and 2 down the right side of the table, or ball 1 may be shifted a little up or down the central line; the limits being when losing hazards become preferable to the cannon.