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KNOW^LEDGE 



[Sept. 7, 1883. 



" Let Knowledge grow from more to more." — Alfred Tennyson. 



Only a small proportion of Letters received can possilly be in- 

 serted. Corresponde.its must not be offended, therefore, should their 

 letters not appear. 



All Editorial comjnitnications should ie addressed to the Editor of 

 Knowledge; all B-usiness communications to the Publishers, at the 

 Office, 74, Great Queen-street, W.C. If this is not attended to 

 delays arise for which the Editor is not responsible. 



All Remittances, Cheques, and Post Office Orders should be made 

 payable to Messrs. Wvman & Sons. 



The Editor is not responsible for the opinions of correspondents. 



No communications are answered by post, eten though stamped 

 and directed entelope be enclosed. 



[915] — With reference to the solution of the problem which 

 appeared in your issue, No. 95, of the 24th inst., as to the height 

 of Galley-Head Light, you have, it appears, assumed the distance 

 to he twenty-one statute miles. 



I think it probable that Prof. Tyndall meant twenty-one nautical 

 miles, which would, allowing for the mean refractive effect of the 

 atmosphere, make the height of the light about 205 feet. 



The light is, as you say, known not to be as high as this, but 

 most likely the data are not very correct. Hundredweight. 



[I cannot see why Prof. Tyndall should be assumed to have 

 meant geographical miles. Most probably he really estimated the 

 distance from the known height of the light. The fiat-earth men 

 think any stick good enough to beat anyone with who talks of the 

 sea's rotundity. — K. P.] 



PUNCTUATION AND PEINTERS. 



[916] — Sir Edmund Beckett's article on this subject is hardly 

 likely to make converts either to his style or his mode of punctua- 

 tion. Here is a phrase which I read several times before I could 

 grasp either its sense or its grammar — " and when he sees that he 

 ought to leave us alone to bear our own iniquities if we let our 

 proofs go 'uupeppered' more than he thinks right." A comma after 

 the word "that," which the jranctual punctuator neglects to supply, 

 would have made his meaning clear. Now, as to style, what about 

 the following sentence ? — " and thereby would raise the indignation 

 of every architect in England into a still hotter flame than it is in 

 just 7101V I see, at my having dared," &c. And again : — " If any- 

 body doubts your opinion of Macaulay's style, which was always 

 mine [not the style, surely ?], iet him try it by the test of reading 

 it [reading what ? the opinion or the style ?] aloud, against Froude's," 

 &c. Sir E. Beckett's letter confirms me in my opinion that one can 

 punctuate another man's work better than one's own. F. R. 



[" F. R." should remember that Sir E. Beckett's communication 

 came as a letter, not as an article, and that he had no opportunity 

 to correct the proof. The contest showed the true meaning of the 

 words "when he sees that" ; no one could suppose that that that 

 (that that that that that " F. R." says refers to) was meant for a 

 conjunction. I have noticed in Sir Edmund Beckett's style that it 

 usually takes for granted a certain degree of attention on the 

 reader's part to the subject-matter. Granted this, no one can ever 

 mistake his meaning, — though one may readily show that, where 

 what he has said and what he is saying is not attended to, a sentence 

 here or there may admit of more than one interpretation. Perhaps 

 it is not unfair to assume that a reader pays a little attention to 

 what he is reading. So much attention as would prevent any one 

 from misinterpreting Sir E. Beckett is not a distraction — like at- 

 tention called away bv over-stopping, &o. — but tends the other 

 way.— R. P.] 



SMALL WHEELS v. LARGE WHEELS. 

 [917] — Mr. Browning's remarks advocating the use of small 

 geared-up wheels for tricycles are sound, and will not be without their 

 effect. But I have lately found out that (contrary to what he sup- 

 poses) they -may also be used for bicycles, with the additional 

 result of making them so safe that they would certainly be brought 

 into successful competition with tricycles on the question of safety. 



I have recently invested^in a bicycle [with ," Sun and Planet " 

 action — a small machine, geared up in the most ingenious way, 

 which cannot add anything appreciable to the friction. (It was at 

 the Stanley show, but little display was made of it.) Though 

 simple, it defies explanation without a diagram, and should be seen 

 in action to understand it ; but the chief point is that the very 

 friction of the pedals on their axles is utilised to increase the speed, 

 and has the effect of gcaring-up the wheel from 40 in. to 50 in. The 

 pedals hang down so that a tall man can ride it. ' "=■ ■ 



Now, if a yet smaller wheel (say 36 in.) were used, the rider's feet 

 could touch the ground when he stopp.ed, and it could be geared-up 

 to 46 in. to 50 in. With such a bicycle there could be no real danger, 

 the advantages of handiness, lightness, and speed would be retained, 

 and no doubt many would ride who would not think of doing so 

 now. S. J. 



REDUCING FAT. 



[918] — What is the use of yon devoting so much of your valuable 

 space to the service of fat people. I am quite sure there are not 

 tv'O " gross fat men " among your many thousands of readers. 



I can prove it, and that easily. Fat men are mostly stupid. 

 Stupid men don't read Knowledge, therefore none of your sub- 

 scribers are fat, and if you have no fat subscribers what is the use of 

 your otherwise useful contributor wasting his energies in this hot 

 weather by seeking to reduce adipose tissue that does not exist. 

 He surely does not aim at reducing fatness in the abstract. I think 

 it has been decided that it is impossible to imagine a fat man in the 

 abstract, and I should like to know how you can administer a 

 towelling to such an individual. 



But what has most annoyed me is your contributor's last article 

 with its remarks on this said towelling. I am as thin as a rake, and 

 for many years I have taken sponge and towel exercise such as he 

 describes, in the belief that it tended to increase of flesh. Now, 

 your contributor comes along and tells me in eft'ect that I have been 

 rubbing it off. Must I, if I wish to accumulate flesh and make the 

 acute angles of my anatomy more circular, to put it scientifically, 

 leave off rubbing and scrubbing ? W. S. 



[The author of "How to Get Strong" was moved to write those 

 particular papers by the appeal of several " heavy weights." He 

 tells me (is it not impolite ?) that he had " Our Editor " also in 

 his eye. But many of the rules for reducing fat are excellent also, 

 he tells me, for adding flesh. Therefore your towelling is probably 

 good for you as well as for us fat fellows. — R. P.] 



DIFFERENT DEGREES OF ILLUMINATION. 



[919] — Some remarks towards the close of the article on the 

 " Laws of Brightness," in last week's issue of Knowledge, induce 

 me to offer you an artist's experience and reflections upon the sub- 

 ject. One of the undertakings I have ventured upon is that of 

 substituting a science of art for the jargon which passes current. 

 In the course of ray studies to this end, the fact that the colour and 

 the chiaroscuro of a picture never have precisely the same values 

 the artist intended, in any but the light in which the work was 

 executed, set me thinking, and this was the form of my conclusion, 

 that the ratios of the different reflecting powers nf objects vary under 

 different degrees of illumination ; and the following was the mode 

 in which I attempted to illustrate the change effected. Take any 

 series of numbers, for instance, 2, 4, 8, IG, then, either the addition 

 to, or the subtraction of the same number from each term of the 

 series, yields two other series in which the ratios of the several 

 terms to each other are entirly altered. W. Cave Thomas. 



COLOURS OF FLOWERS. 



[920] — Mr. Slack, in his " Pleasant Hours with the Microscope," 

 has given us in Knowledge a short but interesting account of the 

 hairs of plants ; how they perform the function of feeders or diges- 

 tive organs by absorbing ammonia and carbon from the air. Plants 

 also, I suppose, absorb silex and other primordial atoms from the 

 soil. Can Knowledge, with the aid of botany, chemistry, and 

 microscopy combined, assist us to understand how colour is formed 

 in flmoers. Colouring matter from plants is a well-known province of 

 chemistry, but how are the varied colours which delight the eye and 

 decorate the garden given to flowers ? Is this capable of analysis 

 or ratiocination ? Lucretius (Book ii.) thought all elementary atoms 

 colourless ; Pliny (Book xxi.) that Nature, in sport, had bestowed 

 the tints which man could not describe. Is this one of the mysteries 

 wherein Nature laughs at the inquisitiveness of man ? — Your 

 obedient, G. G. Hardingham. 



