JuTA- 1, 1887.] 



♦ KNOWLEDGE ♦ 



209 



the Australian eleven and Nottingham, our crack cricketing 

 county, in 188i, when the most perfect display of all-round 

 cricketing science was aflbrded that has perhaps been ever 

 witnessed ; and during the whole of that time not only were 

 no big hits made — very likely that would happen in a base- 

 ball match — but no player was got out, no progress made 

 on either side. Every ball was sent down so dead on the 

 wicket, so craftily pitched, so deftly twisted, that the bats- 

 men dared take no liljerties ; every stroke was so skilfully 

 directed, .so nicely timed, so well adjusted, that the fielders 

 got no chances. It was the perfection of cricket, but — it 

 was a tritle monotonous. 



If it is difficult to compare the batting science in the two 

 games, it is almost impossible to weigh the relative merits 

 of bowling at cricket and pitching at base-ball. Here, in- 

 deed, neither side can doubt the scientihe nature of the art. 

 The cricketer, though he never bowls curves, can see that 

 the curve is a beautiful feature of base-ball pitching ; and 

 the pitcher, though he never sends a ball which touches 

 ground between himself and the batsman, recognises that in 

 a game where this is not only allowed, but essential, 

 there is room for as much science as in billiards, where all 

 the peculiarities in the motion of the ball arise from contact 

 with the cloth. 



The three game« may, indeed, in this respect be ranged in 

 order, though the science of all three be neai'ly equal. The 

 base-ball does not touch ground at all, and none of the com- 

 ple.Kities of movement resulting from contact with a solid 

 surface affect its motion ; but the cuiving derived from con- 

 tact with air is a most delicate and difficult scientific pro- 

 blem. The cricket-ball touches the turf once only (in good 

 bowling) on its way to the batsman ; but a delicixte problem 

 in dynamics is involved in the consideration of the effect 

 arising from the momentary contact of a twisting ball with 

 the ground. And lastly, in billiards, the ball touches the 

 cloth all the time, with etTects arising from the constant 

 variation of velocity alike of advanced rotation, which 

 suggest the most delicate and difficult dynamical problems. 

 Possibly ci'icket, in its intermediate position, supplies the 

 finest opportimities of all three games ; for the bowler might 

 cause the ball to cur\c in the air as well as to twist from 

 the ground ; .and this, in<leed, is what lluckland, the English 

 amateur bowler, is said to intend to try next season. But 

 as yet certainlj' nothing has been done in this way. It will 

 be a matter of curious interest to note whether anything 

 comes from the lessons in curving given to an Eiiglisli 

 bowler of great skill at Phil.adelphia last month, liy a crack 

 American pitcher. (I trust, by the way, this word " crack " 

 Ls in use in America, as with us, to mean first-rate. I beg 

 the compositor not to set it crank.) 



The curving in l).ase-ball is a more difficult problem to 

 deal with scientifically than twisting at cricket. It is much 

 less easy to make experiments in curving. The effect of 

 twisting is very easily tested, even in (he length of a room ; 

 but for the curve such sharp propulsion (as well as rotation) 

 is required that experiments can only be made in the field. 

 The problem is one of the prettiest hydrodynamical pro- 

 blems known. (I am quite aware that the word hydro- 

 dynamical must here seem entirely out of place ; but in our 

 treatises on hj'drodynamics, fluids as well as liquids .are 

 considered, and the student who wishes to deal with the 

 curving problem scientifically mu.st turn to treatises on 

 hydrodynamics for the necessary formulas.) Every ball 

 flung through the air is in greater or less degree deflected 

 from the course it would have in a vacuum, whether it spins 

 or not. The parabolic path of a projectile is a myth so far 

 as projectiles in air are conceined ; and an artillerist who, 

 knowing the velocity of the Imll at the cannon's mouth and 

 knowing the angle at which the cannon is inclined, were to 



calculate the place where the ball would fall on the ordinary 

 parabolic idea, would be out not only by a few yards, but 

 by hundreds, in some cases by thousands. A base-ball is 

 pitched sharply enough to deviate measurably from the 

 parabola, without any spin at all. It carries in front of it 

 a little cone of compressed air, which is all the time opposing 

 its advance with an action akin to that of a spring. 



But this effect is one which the batsman would take into 

 account as unconsciousl)', and therefore as uniformly, as a 

 man does who catches a ball pitched to him from a long 

 distance and really travelling yards from the parabolic path ; 

 for the slowing of the ball on account of atmospheric 

 resistance takes place in a uniform way. When, however, 

 the ball is pitched with a sjiin which carries one side of its 

 advancing face forward and the other back, the cone of com- 

 pres.sed air in front is no longer symmetrically adjusted. 

 The compression is greater on the side carried forward by 

 the spin, and less on the side carried backward ; for on one 

 side the air is not able to slip past the ball so readily as on 

 the other, and naturally gets compressed on that side when 

 its passage is impeded by the friction of the spinning ball. 



Now, a cushion of air, though not so hard as the ground 

 or as a billiard cushion, has resisting power all the same. 

 The ball, resisted on that side, is deflected to the other. An 

 odd thing in seeming, though the mathematical equations 

 explain it, is that the deflection does not begin from the 

 beginning or increase gradually, but nearly all of it seems 

 to take place after the ball has passed a certain distance, 

 varying according to the initial velocity. It is this, indeed, 

 which makes the curve so eflective in deluding the batsman. 

 The twist at cricket, as at present chiefly used, has no 

 tendency to cause the ball to curve in the air. One side or 

 other of the ball is sharply brought down, so that the axis 

 of rotation lies in the ball's track, and the ball begins, as it 

 were, to I'oll the moment it touches ground, so that though 

 the touch is instantaneous only, the ball is sensiljly 

 deflected. 



<B aiV* 



By Eichard A. Proctor. 



The article on large telescopes quoted in this month's 

 Knowledge from the Xfiv York fVvrkl is well meant, as 

 readers will notice, and I think most English students of 

 .science, at any i-ate, will admit that, while I have been 

 generous, to say the least, towards American astronomers 

 ever since I wrote about astronomy at all, nothing in that 

 article is inconsistent with what I have elsewhere written. 

 Yet, somehow, the publication of this article in the widely- 

 circulating columns of the ]Vorll has brought down upon me 

 a small cyclone of mixed reproaches and misrepresentation. 



First, Professor Young, who assuredly has had small 

 reason to complain of anything I have said of his work in 

 the past, complains bitterly now because I have suggested 

 that the kind of work he is doing with the very fine telescope 

 placed in his hands at Princeton College, N.J. (expressly, 

 be it understood, that he should go ahead of his former self, 

 as well as of his great English rival, Mr. Huggins), is of 

 veiy little real value. True he has done work which he 

 could have done with no smaller telescope — he has measured 

 positions of Phobos and Deimos, those two faint satellites of 

 Mars, and (I believe) of Hyperion, the seventh and most 

 difficult satellite of Saturn, while a number of close double 

 stars and very minute companions have had their distances 

 and ])Osition-angles measured by him, or under his superin- 

 tendence. But when the value of all this towards the 



