498 



NATURE 



[Septp:mber 24, 1891 



preserve its form under gravity, the ball (when it struck 

 the face near the centre) always penetrated to a depth 

 of more than one diameter, and splashed fragments of 

 the clay to a considerable distance. These were usually 

 replaced, and the surface levelled for a fresh experiment, 

 as soon as the ball was dug out. The speed of 300 feet 

 per second, thus measured, may be taken as an inferior 

 limit to the initial speed in a really fine drive. 



It thus appears that the resources of mere particle 

 dynamics are quite insufficient for the adequate solution 

 of the problem of long driving ; though, of course, they 

 fully meet all questions connected with mere approach 

 shots ; and that the rotation of the ball must play at least 

 as essential a part in the grandest feature of the game, as 

 it has long been known to do in those most distressing 

 peculiarities called heehng, toeing, sHcing, &c. But when 

 this is once recognized, it is only the beginning of sorrows ; 

 for even the approximate treatment of the eddies pro- 

 duced by the rotation appears to be at present beyond our 

 powers. 



In order that the path of the ball may be (for a short 

 time) approximately straight, still more if it is to be con- 

 cave upwards, the downward acceleration due to gravity 

 must be neutralized by the effects of a rotation due to 

 undercutting. [Of course enormous speed could pro- 

 duce the approximately straight path, but not the con- 

 cavity.] Hence the necessity for a tee, unless the 

 turf be exceptionally soft, in order that the club may 

 impinge on the lower part of the ball. Hence also one 

 important use of hammering, viz. that the undercut ball 

 may take as rriuch angular velocity as possible : — the other 

 being that the spin, so acquired, may tell as much as 

 possible during the flight. The gist of the matter is thus 

 seen to be : — For steady flight the ball must have rotation 

 of some kind. The best mode, that of a rifle-ball, is of 

 course unattainable. The others produce respectively 

 heeling, toeing, dooking, and soaring. Of these the last, 

 alone, is not necessarily disastrous ; and it is therefore 

 to be adopted. 



I have not hitherto succeeded in my attempts to apply 

 even approximate calculation to this altered set of con- 

 ditions : — but it is easy to see, without calculation, that 

 the longer the path of the ball retains nearly its initial 

 inclination to the horizon (even if, in achieving this, it 

 should have to expend part of its energy of translation 

 along with that of rotation, and thus diminish the range) 

 the longer will be the time of its flight during the carry. 



And, as a practical deduction from these principles, 

 it would appear that to secure the longest possible 

 carry the ball should be struck so as to take on con- 

 siderable spin : — so that the ideal driver should be in 

 truth a Bulger, but with the important variation that its 

 bulge should be of considerable curvature and in a 

 vertical, not a horizontal plane. The height of the most 

 prominent part of the face (above the horn) must of course 

 be less than the radius of the ball How much less can be 

 found only by trial. And, in addressing the ball, the player 

 must stand directly opposite to it. Such clubs, however, 

 could be profitably used only by really good players : — 

 men who can hit with what part of the club they please. 

 The reckless swipers of the present generation, who slash 

 away anyhow, and (with ordinary clubs) manage occasion- 

 ally to make a really " tall " drive, will probably smash 

 the proposed form of club on the very first appearance of 

 topping. As to those who propel the ball by " skittling " 

 rather than driving, any change 7nust be an improvement, 

 so that they should welcome the proposed novelty. The . 

 matter is a very simple one. A few touches skilfully 

 applied with a rough file, and the new system rises at 

 once out of the old. 



There is one other point on which opinion seems to be ' 

 so unsettled that an allusion may be made to it here : — 

 the effects of weather on the carry of a ball. Of course, 

 other circumstances being the same, the only direct effect 



NO. II 4 3, VOL. 44] 



is on the coefficient of resistance. If this be taken as 

 proportional (roughly) to the density of the air, it may 

 vary, in this climate, to somewhere about ten per cent, of 

 its average amount, by increase or by diminution. It has 

 its greatest value, and the drive is accordingly shortest, 

 on a dry cold winter day with an exceptionally high baro- 

 meter. The longest drive will of course be when the air 

 is as warm and moist as possible and the barometer very 

 low. p. G. Tait. 



HOOKER'S ''/CONES PLANTARUM." 



'X*HE recent issue of the fourth part of vol. xx. of 

 -■■ the entire work completes the volume, and closes 

 the third series, with a total of two thousand plates. 

 This useful, and now indispensable, publication was com- 

 menced by the late Sir William Hooker in 1837, and the 

 first volume was dedicated to the late George Bentham, 

 who is described in the dedication as an " ardent pro- 

 moter, not less by his patronage than by his writings, of 

 botany and horticulture." Sir William Hooker started 

 the " Icones" to illustrate some of the numerous novelties in 

 the collections which were pouring into his herbarium from 

 various parts of the world, especially from the southern 

 hemisphere, at that period. With a few exceptions by 

 Harvey, Gardner, and others, the drawings and descrip- 

 tions were by Hooker himself, and a volume, containing 

 one hundred plates, appeared annually, or nearly so. The 

 first series closed with the fourth volume in 1841. At 

 this date the founder was already Director of Kew 

 Gardens, and he continued the work to the tenth volume, 

 which terminated the second series. Two or three of the 

 later volumes of this series were illustrated by the then 

 rising botanical artist, W. H. Fitch. In the tenth volume 

 we find a dedication of the whole ten volumes to George 

 Bentham, in much the same words as the first. This was 

 in 1854. After an interval of thirteen years, the third 

 series was commenced, under the editorship of Dr. J. D. 

 (now Sir Joseph) Hooker ; and G. Bentham, D. Oliver, 

 and J. G. Baker were contributors. Mr. Bentham, we 

 believe, financed the undertaking. This, the eleventh 

 volume, was not completed until 1871 ; but it is a most 

 interesting volume, illustrated by Fitch, and containing 

 among other things many of the endemic plants of St. 

 Helena. The second volume of this series, the twelfth of 

 the whole, was also illustrated by Fitch, and is valuable 

 for the figures of curious new genera founded by 

 Bentham and Hooker when elaborating their " Genera 

 Plantarum." 



On the completion of this volume, in 1876, a difficulty 

 arose, consequent on the retirement of the artist, though 

 there was no actual interruption in the appearance of the 

 parts. But it was impossible to replace an artist like 

 Fitch. Indeed, the only alternative was to train a person 

 to do the work. This was not so easily accomplished ; 

 there were failures, and so high a standard of excellence 

 has not since been reached. Nevertheless, the present 

 artist gives as good drawings as could be expected from 

 dried, flat specimens, and the botanical details are usually 

 as full as is necessary, if not all that could be desired. 



Since Mr. Bentham's death, in 1884, the work has 

 proceeded with greater rapidity, and is now appearing at 

 the rate of a volume per year. It is now published at the 

 expense of the Bentham Trustees,^ and sold at about half 

 the former price ; and since his retirement Prof. D. 

 Oliver has undertaken the editorship. Under such 

 favourable auspices, together with the abundance of 

 material in the Kew Herbarium, it is confidently hoped 

 that the interesting character of the work will be iuUy 

 maintained, and that the mechanical production of it will 

 be improved, resulting in a larger sale. The later volumes 



' Of a fund beqi eathed by Eentham for the advancement of botanical 

 science. 



