Fig. 1
Now, for practical purposes the cloth and bed of the table are level, and the balls are of the same size; hence when they touch one another the point of contact is invariably on the line of their greatest horizontal circumference, which, as all know, is precisely at half their height. It will hereafter be shown that ball 1 may be caused to leap, and so strike ball 2 above this; but for present purposes, when a plain stroke alone is being considered, it may be accepted as a fact that the point of impact is always at half the ball’s height. That fixes the location of impact vertically; but horizontally it is evident that there is considerable latitude. Ball 1 may hit ball 2 either precisely full, when the centre of one is played on the centre of the other, or it may strike either to the right or left of the centre of ball 2; the limit on either side being the finest possible touch. The accompanying figure will show what is meant. When ball 1 hits ball 2 full, at the moment of impact it occupies the position 1″; and the part of 2 which can be struck by a ball situated at 1 is from P″ to P; if ball 1 occupies the position 1′, then the part of 2 which may be touched is restricted to that marked P″ P′; but should ball 1 be placed at 1″, then the only point on 2 it can touch is P″. Therefore the nearer 1 is to 2 the less of the latter can be struck, and the further away the more.
As regards the division of balls, for the English game at any rate, the simpler it is the better. The larger balls on a smaller table, as used in the French game, admit of more minute subdivision than do our smaller balls, which may be, and often are, further from the player’s eye. To attempt a division which the eye cannot easily appreciate is a mistake. For purposes of play both balls 1 and 2 must be divided; and although at this early stage of the manual we are not concerned with the division of ball 1 (for all practice at present is confined to centre strokes), yet it is convenient now to record the divisions of both balls.
Ball 1 is divided by its vertical and horizontal diameters into four parts. The centre stroke is delivered at C, and is of all strokes by far the commonest and most important.
A ball struck high and right is struck in the sector C A E; low and left in C D B; high and left in C A D; low and right in C E B.
The vertical and horizontal lines are divided from the centre where they intersect, into four equal parts each way. Thus a ball ¼ high is struck on the line C A at the point marked ¼; ½ low is struck on C B at the point marked ½; ¾ right is struck on C E at the point marked ¾; ¼ left is struck on C D at the point marked ¼. Combinations of these divisions are of course possible: thus ½ high and right would indicate a point P; ¾ left and ½ low is represented by P′. That division is quite as minute as the eye can follow; indeed, for general purposes it will probably suffice to indicate the sector only; to say, for example, ball 1 should be struck high and right.
Fig. 2
