Dbc. 16, 1881.] 



KNOWLEDGE 



143 



Continued from page IW.J 

 thorn to drink, and as the supply is only small, they naturally 

 ^aw through the pipe. This, in my opinion, is the more correct 

 view than to imagine thev reason from hearing the fluid pass 

 through the tube. " W. Maeshali,, F.B.S.E. 



ELEMENTAEY ELECTRICITY.— SCIENTIFIC MEETINGS.— 

 MYSTEUY OF " PSYCHO." 



[126] — Having read letter (No. 73), signed "Daniel Jones," I 

 should like to point out that it seems to me very undesirable that 

 you should use your valuable columns for any such papers, which 

 can bo read in any good text-book on electricity. 



May I suggest that you shonid find room in your columns for a 

 notice of times and days of the meetings of scientilic societies 

 during the ensuing week, with the titles of the papers to be read. 



I should also like to ask through your columns whether a solution 

 of the mechani.sm employed in the automaton " Psycho " has ever 

 boon given ? — Yours, tic. H. W. 13. 



[We quite agree with our correspondent on the first point. As to 

 the second, we believe that only a small proportion of our readers 

 care to know the days on which the various scientific societies 

 meet ; and that all who do care, must be in the way of learning 

 those dates elsewhere. It seems, therefore, better for the greater 

 number — by far the greater number — to save for other purposes 

 the space which such notices as " H. W. B." suggests would occupy. 

 —Ed.] 



NAMES OF STABS. 



[127] — I am making a collection of the ancient names of stars. 

 In this I have been much assisted by the list given in your larger 

 .\tla3. I should be very much obliged to yon if you could point out 

 ;iny books in which I could find more of these names, as well as 

 any traditions about them. A friend of mine, who is an Arabio 

 scholar, has promised to translate those which arc not tfio much 

 corrupted. It seems a pity that these names should stand a chance 

 of being forgotten, as much of the popular interest in stellar astro- 

 nomy dies out when stars are only designated by a letter in 

 a shapeless constellation. Apologising for thns troubling you, 

 Yours, Ac, J. H. Thomson. 



R. A. Mess, Shoeburyness, Nov. 28, 1881. 



[There is much that ,will interest Mr. Thomson in " Smyth's 

 Bedford Cycle," the old edition. From the new one we understand 

 the matter in question has been removed. — Ed.] 



DONATI'S COMETS. 



[128] — In Figures I. and IT. on page 49 we have two pictures of 

 Donati's comet, as also, judging from the stars given in the dia- 

 grams, the distance and direction travelled by the same. Now, if 

 the stars depicted on the plate have relative places in the firmament, 

 the comet must have been travelling in a side direction, and conse- 

 quently the tail mnst not have been pointing from the snn. 



A Young Astkonomeb. 



[The picture is right. There is no such difficulty as " Y. A." sup- 

 poses. The comet's path is not on a line towards the sun. — Ec] 



PASTEUR'S PLATES OF GERMS, &c. 



I [129] — Would Dr. A. Wilson, if possible, kindly give us Pasteur's 



plates in connection with the subject. He may intend to do so ; if 



1 80, my suggestion is premature. I am sure they would be interesting. 



' A friend, a few years ago, lent me Pasteur's plates on the germs 



generated in brewing, and many a pleasant hour have 1 spent 



I in trying to obtain the different germs by erperiments on beer, 



yeast, &c. 



I have read a good many of the scientific papers of the day, but 

 hare never been so interested in any of them a.s I have in Knowledge, 

 •rhich, I feel sure, has only to be known to be a complete success 

 I and boon to the public. — Believe me yours, &c. 



" F. C. S. 



COLOURS IN ANIMALS AND PLANTS.— DARWIN ON 



WORMS.— REASONING ANIMALS. 

 [130] — The tendency of men of science to run investigation to 

 extreme tenuity is become a danger. Knowledge whittled to a 

 I pomt is knowledge reduced to nothing. Casual inquirers recoil 



from infinitesimals and the overwrought. 



I Dr. Wilson, in Knowlege, No. 2, labours to show that the colours 



I of wild birds and beasts are designed by Nature to obscure the 



I animals from their enemies, and, when predatory, from the eyes of 



their prey. It might be affirmed that the colours of flowers are 



oeaigTied to put the flowers conspicuously before the eyes of men 



and insects. Nature is not given to special amenities and provi- 



dences. The dark colours of the sole and the fljunder are no 

 protection. When in repose, they are concealed by a cover! ig of 

 sand. 



Mr. Darwin's theory of worm action on the soil is, to my mind, 

 an elaboration of exceptional minutia; to huge paradox. 



The paper on Intelligence in Animals is in another category. 

 Anyone capable of accurate observation, and daily among them, 

 knows that animals do reason. 1 could name many instances, but 

 one shall suffice. A duck came opposite our day-room window, 

 which looks into the orchard. Mrs. D. noticed her uneasiness and 

 persistent waiting, and concluded that it indicated hunger. She 

 took madam duck some corn. The food was simply looked at, but 

 the look was followed by movements that plainly meant " come with 

 me." The request was accorded to, on supposition that the duck 

 was shut out of her cote. But, no ; the cote was open, and the 

 duck urged "come on, come on." She led to a hole in the hedge 

 that fenced the stackyard from the orchard ; and there, on the 

 other side, was a lame duck, that could not make passage of the 

 hole, in a fever of despair. Mrs. D. went round and brought the 

 poor bii-d into the yard. Meanwhile, the kindly-hearted duck made 

 her way to where she knew her mistress would return, and the rest 

 of the flock gathered irith her. The meeting of the two ducks was 

 a little drama. Between them there was a wonderful talk, soon 

 joined in with by the whole flock ; and they marched off with what 

 was taken to be loud cheers. 



Reason ! Surely animals, furred and feathered, reason j some 

 better than others, but all reason. The fox is a rapid and acute 

 reasoner. 



I hare but limited intimacy with pigs. So far, however, as 1 

 am acquainted with them, nothing is so manifest to me as that they 

 reason ; and thej- are humorous and inclined to fun, when at 

 liberty. A well-knovm sportsman had a pig for pointer. Dogs all 

 reason, the high-bred sheep-dog in particular ; and more, under- 

 stand sentences of speech addressed to them directly, or in their 

 hearing, and in the latter case, they will, if so minded, circumvent 

 you on the knowledge they have gained. 



Ducks and dogs have the human propensity to sulk with you, or 

 with one another. 



Memory, no observer will deny them. Bnt is not an effort of 

 memory reasoning ; calling together ideas previously known, and 

 linking them, absolutely or tentatively, in sequence, till the desired 

 lost idea is regained ? 



Professor Jevons' logical abacus, in work, really represents the 

 mode of an effort of memory, as well as a logical concatenation. — 

 Yours faithfully, B. DoNBAVAND. 



Picton, Chester. 



ATMOSPHERIC ABSORPTION AND TERRESTRIAL 

 RADIATION OP HEAT. 



[131]— In his " Heat a mode of motion," (1880) page 317, Prof. 

 TyndaU says : — '■ I never on any occasion suffered so ranch from solar 

 heat as in descending from the ' corridor' to the grand plateau of Mont 

 Blanc on Aug. 13, 1857. Though Mr. Hirst and myself were at the 

 time hip-deep in snow, the sun blazed against us with unendurable 

 power." Mr. W. Mattieu William's letter 68, page 96, and 

 B.M., F.R.C.S., No. 36, page 77, bear similar testimony. I think 

 Prof. TyndaU explains the whole matter (page 317). '' The 

 beams of the sun penetrate glass without sensibly heating it ; the 

 reason is, that having passed through our atmosphere, the heat has 

 been in a great measure deprived of those constituents liable to be 

 absorbed by glass." Prof. TyndaU refers to the invisible (the 

 hottest) rays, see page 316. It seems to me too much stress is placed 

 on the atmospheric absorption of terrestrial radiation. From the 

 foregoing references a large proportion of the sun's invisible rays 

 are intercepted before they reach the earth ; and then all those 

 which do impinge on the earth raise its temperature, and by " con- 

 vection," more heat is transferred to higher altitudes of the air, so 

 that only a comparatively small proportion of the heat is radiated 

 from the earth compared with what enters the atmosphere as solar 

 radiation. J. A. L. R. 



[A large portion of the invisible solar rays remain (compare 

 figs. 112 and 113 in Tyndall's book) after passing through the air, 

 and to these, constituting at least twice the visible rays, the 

 reasoning of Mr. Dyer (in letter 20, p. 56) applies. — Eh).] 



"KNOWLEDGE" AND THE SCIENTIFIC SOCIETIES. 



[132] — I see that some of your readers arc asking for Reports of 

 the Proceedings of the Learned Societies, and that you have replied 

 very practically by showing them a sample of what the most meagre 

 outline would amount to. 



In confirmation of your decision, I may state my own practical 

 experience. When my genial friend, the late George Dawson, 

 started the BirmingTiam Morning Ne^vs, I undertook the functions of 



