243 



KNOWLEDGE. 



June. 1911. 



and some notes on the " Elimination of Sparking " are con- 

 tributed by the staff and students of the Electrical Engineering 

 Department. 



.•\n important contribution to the subject of \'entilation is 

 made by Professor J. Radcliffe. 



A number of new methods in Volumetric Analysis are 

 described, also a modification of the Beclcmann apparatus by 

 Dr. Knecht. The dyeing industry receives a large share of 

 attention, especially in its application to cotton fabrics, 

 while even the colouring matter in niunnny cloths has been 

 investigated I 



Weaving, of which we should have expected to hear much, 

 has only one short paper devoted to it. This, a twelve page 

 monograph on " The Effect of Twist upon Yarns," consists 

 mainly of a detailed description of three plates depicting 

 " single " and " double '" yarns in various stages of twist. 



The report to the Government on the Hand Loom Industry 

 in Bombay is also included in the \olume. 



The journal is printed in the Printing Crafts Department of 

 the School, on which it reflects some credit. 



P. K. 



CORRESPONDENCE. 



H.ALLEY'S COMET. 

 To flic Editors of " Knowledge."' ' 



Sirs, — I shall be glad if any one of your readers or 

 contributors of astronomical articles will please explain to 

 me, through " Knowledge." why the tail of Halley's Comet 

 was shown divided into one on the east before dawn, another 

 on the west after dusk, instead of one on the north and 

 another on the south, when our globe entered into the tail 

 of the comet in the morning of the 19th May, 1910. Is the 

 cau.se of the division of the tail the magnetic repulsion of 

 the earth ? 



I should also like to know whether the tail of Halley's 

 Comet actually touched the atmosphere of the earth or not? 



K. G. CHANDR.^. 



THE ETERNAL RETURN. 

 To flic Editors of " Knowledge." 



Sirs, — I should like to say a few words on the above 

 subject. I have dealt with the matter from the theological 

 point of view in two letters which have recently appeared in 

 the \c'iC Age criticising some articles on " Theology " by 

 " M.B. Oxon." 



First, it is necessary to realise that one's know-ledge of the 

 ■' external w-orld " and the phenomena which occur there is 

 primarily obtained by sensations, these sensations necessarily 

 depending upon the nature of the corresponding sense organs. 

 Most of us think principally in visual impressions Iretinal 

 images) ; and since the shape of these images depends upon 

 the structure of the eye, it is open to question to what extent 

 the relation of the images in the mind is a true representation 

 of the '■ external " phenomena. 



Space, time, force, motion are so intimately associated with 

 " consciousness " that there is a good deal of reason for 

 asking whether they really exist apart from consciousness. I 

 often wish scientific people felt more than they appear to 

 do, that whatever line of investigation into the underlying 

 processes of nature is taken, the rock-bottom arrived at is 

 the consciousness of the investigator. One may reduce the 

 whole cosmos, including humanity, to motion and force — but 

 these are effects in consciousness. 



It is very gratifying to see the notion of space of more than 

 three dimensions entertained by Professor Pickering, If only 

 the conception were more readily entertained by astronomers, 

 physicists and biologists, many astounding results might follow. 



The possibility that the bodies of the solar system are 

 something more than spheres, as a sphere or cylinder is 

 something more than a circle — the possibility that organisms 

 (including man) are something more than three-dimensional 

 entities — opens up a province of speculation which might not 

 be devoid of practical results. However, since dimension 

 depends upon consciousness, one has to be careful in talking 

 of dimensions of which the human mind is not " consciously " 



^°""'='°""- J. JOHN ELLIOTT, 



COSMIC CHANGES. 

 To file Editors of " Knowledge." 



Sirs, — In the recent work of Dr. .Alfred Russel Wallace, 

 " The World of Life," the following statement occurs 

 " , . . . there have been cosmic changes due to the varying 

 eccentricity of the earth's orbit and the precession of the 

 equinoxes, leading to alternations of hot. short summers with 

 long, cold winters, and the reverse ; culminating at very 

 distant intervals in warm and equable climates over the 

 whole land surface of the globe ; at other shorter and rarer 

 periods in more or less severe " ice ages," like that in which 

 the whole north temperate zone was plunged during the 

 Pleistocene period, , , ," 



Can any of your readers give a proof of the cosmic changes 

 due to varying eccentricity and precession of the equinoxes ? 



•AN.XIOIS." 



IS SPACE INFINITE? 



To the Editors of " Knowledge," 



Sirs, — Surely it is easier to conceive of infinity than of 

 finity ? In considering this ijuestion one must assmiie that one 

 has the power of illimitable flight ; one must deal with the 

 question on a practical basis. Your correspondent talks about 

 curved space. Now, however slight is the curve, some sort of 

 limit is suggested of which we are on one side. What is on 

 the other ? Either absolutely nothing, i.e.. infinity or something, 

 in which case we should have to start afresh. To my mind 

 the very fact of talking of finity, tacitly admits infinity. Directly 

 one talks about a boundary, the "other side" must always be 

 considered. 



It is also interesting to speculate about time, such as we 

 know it. Suppose that all our systems by which we measure 

 time were taken away, and that man lived on the surface of a 

 dark earth, let us suppose, absolutely the only sphere in 

 existence, — would time still be considered to exist ? It would 

 exist, and yet it is strange to think upon. CHER 



SCIENTIFIC NOTES. 

 To the Editors of " Knowledge." 



Sirs, — In reading a paper by William R. Kenwick on 

 " Insects Destructive to Books" reprinted from The American 

 Journal of Pharmacy, I came across the following which is 

 well worth attention : — " Too little attention has been given to 

 the manuscript notes of scientific workers, often only a line or 

 two of their observations upon the small forms of life. The 

 average scientific man, thinking it too trivial to notice, often 

 passes over the very observation which is the key to the puzzle 

 that he has been spending years in trying to sol\e." 



It cannot be emphasized too strongly that real advance in 

 knowledge, in any branch of science, is only to be made by 

 the worker who pays attention to the minute details, and who 

 regards nothing as too trifling to be worthy of record. 



FRANK C. DENNETT. 



