58o 



NA TURE 



[Oct. 20, 1887 



Pictorial Geography of the British Isles. By Mary E. 



Palgrave. (London : Society for Promoting Christian 



Knowledge, 1887.) 

 This volume, although it could not be used as a text-book, 

 might be of considerable service to young students of geo- 

 graphy. The pictures would probably excite their interest, 

 and would certainly tend to give definiteness to some of 

 their conceptions. The letterpress is, upon the whole, 

 very good. Beginning with a chapter on how our scenery 

 was made, the author gives what she calls " a summary 

 of British scenery," and then proceeds to describe the 

 coasts, the mountains and hills, the plains and rivers, 

 and the lakes and islands of the British Isles. There 

 are also chapters on historical scenery and industrial 

 geography. 



LETTERS TO THE EDITOR. 



\The Editor does not hold himself responsible for opinions 

 expressed by his correspondents. Neither can he tmder- 

 take to rettwn, or to correspond with the writers of, 

 rejected manuscripts. No notice is taken of anonymous 

 comtnunications. 



[The Editor urgently requests correspondents to keep their 

 letters as short as possible. The pressure on his space 

 is so great that it is impossible otherwise to insure the 

 appearance even of communications containing interesting 

 and novel facts.'\ 



The Spectator and Science. 



In a recent number the Spectator discussed a rumour that an 

 American inventor had discovered a compound which possessed 

 the peculiar property of exploding "forward only." The matter 

 was discussed quite seriously, and it was pointed out that if the 

 report were correct the defence of the northern frontier of 

 India would be facilitated, as it would be possible to substitute 

 parchment for metal in the construction of guns. So enamoured 

 was the writer with this idea that it was again referred to in a 

 subsequent article on "The New Air-Cannon." 



Upon this I ventured to address to the editor a short note, in 

 which I pointed out that as it is improbable that the most 

 ingenious inventor will now upset the law that "action and 

 reaction are equal and opposite," the rumour might be safely 

 discredited. 



More than one number has since appeared, but no steps have 

 been taken to remove the misconception which the serious 

 discussion of an absurdity must have produced on the minds of 

 many non-scientific readers. 



It may be, of course, that the Spectator would consider it a 

 useful exercise to discuss what would follow if perpetual motion 

 were realized or the circle squared. If so, there is nothing more 

 to be said, except that the grave application of such speculations 

 to questions like the defence of India is apt to mislead. It may 

 perhaps be added that such a habit is not likely to increase the 

 respect with which the opinions of the paper are received when 

 it plunges hotly into a controversy of practical importance on 

 scientific methods, such as that on the utility and morality of 

 vivisection. 



It is, I believe, a subject of regret to others besides myself 

 that a journal, the attitude of which on other matters we admire, 

 should betray such obvious ignorance on matters scientific. 

 Before the Spectator discusses yachts' bottoms, new air-cannons, 

 and compounds which explode forward only, it would be well 

 for the management to olitain the advice of someone who has 

 a competent knowledge of the scientific problems involved. 



October 10. Arthur W. Rucker. 



"Toeing " and " Heeling " at Golf. 



I WAS much interested in the " Unwritten Chapter on Golf" 

 (Nature, Sept. 22, p. 502), signed with the well-known initials 

 of "P. G. T." The mechanical explanation of "toeing and 

 heeling," is however incomplete, as it does not take into account 

 the torsion of the head and shaft caused by the impact of the 

 ball on one side or other of the centre of percussion. If the ball 

 be "heeled " (that is, goes off any point of the club-face nearer 

 to the heel than the centre of percussion), the impact on the 



club-head causes it and the shaft to twist horizontally from right 

 to left, a movement that is plainly felt in the hands as a dis- 

 agreeable jar. Even should the club-face approach the ball in 

 a line perpendicular to the direction of the intended drive, it no^ 

 longer remains so on meeting the ball. 



In the best driving the club follows the ball nearly to the 

 extent of the swing, so that before they part company, the 

 elasticity of the shaft twists the club- face back to or beyond its 

 normal position, which should be perpendicular to the line of 

 drive. If the ball happens to be "toed," the reverse movement 

 takes place. A curve to the right in the course of the ball so 

 invariably follows "heeling," even with the best drivers, and a 

 curve to the left (but not so frequently) " toeing," that they have 

 become recognized by golfers as cause and effect. I have always 

 looked upon the torsional movement described as the main cause 

 of the horizontal rotation given to the ball, and still think that 

 any explanation which leaves this uncon^^idered is incomplete. 



T. Mellard Reade. 



Park Comer, Blundellsands, September 24. 



[The cause spoken of by Mr. Reade has occasionally some 

 little effect, and I was fully aware of this long before I wrote 

 my article. But, as most golfers know to their disgust, a ball 

 can be badly "heeled" or " toed " when driven by a club or a 

 cleek with the most untwistable of shafts. I should thus have 

 confused instead of enlightening the ordinary reader, had I 

 entered upon such a subsidiary question as tiiis effect of torsion. 

 For my own part, I believe that the most serious effects of 

 torsion are produced before the club reaches the ball. This is 

 not alluded to by Mr. Reade. 



Mr. Reade uses the word "heeling" in the literal sense of 

 " striking with the heel of the club," and has thus been led to 

 state the opposite of the facts. If he will think over the result 

 of the impulsive rotation of the club-head, which is due to small- 

 ness of torsional rigidity in the shaft, he will see that (supposing 

 the club-face at impact to be exactly perpendicular to the course 

 desired) hitting off the heel tends to produce what is commonly 

 called "toeing": — i.e. skewing to the left! Similarly, hitting 

 off the toe will produce what is commonly called "heeling " : — 

 i.e. skewing to the right ! Thus the torsion of the shaft tends 

 to mitigate ordinary " heeling " if the heel of the club be used^ 

 and to intensify it if the toe be used. Surely this would not 

 have been easily understood by the ordinary reader of news- 

 papers, for whom my article was written. — P. G. T.] 



The Fertilization of the Coffee Plant. 



I SEND you the following notes on the fertilization of the coffee 

 plant (C. arabica) which I made some time ago, and which may 

 be interesting to those who study the subject. 



Your readers are doubtless aware that coffee was cultivated 

 some twelve years ago to a very large extent in Ceylon and South 

 India, but owing to the attacks of leaf disease, the area has been 

 rapidly reduced, except, I believe, in some parts of Coorg and 

 Mysore, where the climate is drier, and the leaves suffer less 

 from the fungus. It has now been largely replaced by tea. 



The jasmine-like flowers of the coffee are borne in clusters in 

 the axils of the leaves, and appear simultaneously all over tho 

 estates. After a prolonged drought of one or two months, 0; 

 even more, at the beginning of the year, there is generally 

 heavy fall of rain, sometimes lasting only an hour or two, some 

 times continuing for two or three days : the amount that falL 

 must be enough to saturate the ground, and should not be I ~ 

 than one inch. 



In from six 'to eight days from the time of the first showi 

 the flowers burst into full blossom, last for a day, and then droj 

 off. On the evening before the blossom is fully out, if th- 

 flowers are examined it will be found that they are partiall; 

 open, the stigma being protruded and receptive. During th^ 





V 



night the hum of insects can be distinctly heard, and I am of 

 opinion that the flowers are largely fertilized by night -flying 

 insects which carry pollen from those flowers which happen to 

 be open rather before the others, as some are delayed. On 

 the following morning all the flowers will be found open, ami 



