Concerning another short drive of the same class, Professor Tait remarks: “In spite of its 50 per cent. greater angle of initial elevation, the carry of the non-rotating projectile is little more than half that of the other, and it takes only one-third of the time spent by the other in the air. But the contrast shows how much more important (so far as carry is concerned) is a moderate amount of under-spin than large initial elevation. And we can easily see that initial elevation, always undesirable (unless there is a hazard close to the tee), as it exposes the ball too soon to the action of the wind where it is strongest, may be entirely dispensed with.” A question which may have been in the reader’s mind for some time is as to whether, since the effect of under-spin is to make the trajectory turn upwards as it were, excessive under-spin would not result in the ball taking an absolutely upward trajectory and then curling over and right round. In actual practice so much under-spin could not be put on to a golf ball as would enable it to get the better of gravity and other circumstances to this extent, but theoretically such an evolution would be described if the conditions were equal to it. Professor Tait says: “The kink can be obtained in a striking manner when we use as a projectile one of the large balloons of thin rubber which are so common. We have only to ‘slice’ the balloon sharply downwards in a nearly vertical plane with the flat hand.” It must be remembered that in the case of a very bad slice the ball sometimes does actually curl right round towards the finish of its run. VIII