32-i 



KNOWLEDGE 



[FKa 10, 18S2. 



[242]— I'liOHK CoHi'OidTloN. — Will yon kindly «Io mo the fuvoiir 

 of miyin^ wlto^** wurk yoti conaidor to bo tho hcHt r>n Engliiili proso 

 comjiositioii ? — Stanislas. 



[213] — Aiii-Pi'Mp. — (1.) I Imvo II Hmnll nir-piini)) with one Imrri'l. 

 1 hnvo liioil 111 filter morcnr)- thioiiKh ii little rnno filter sold fur 

 the piir|>os(', 'lilt without Hiicicss. Would Homo reader of Ksow- 

 LRnOK kindly give mo ii reason for this ? Does the experiment 

 require n stronger pump ? (2). Would some render mention a book 

 containing pxpcriments with the nir-pnmp ? — X. X. 



[2i4]— LrcniiKs. -I wish to give a few Hcientific leetures to 

 young people, and should be grateful if some one would suggest 

 good subjects, telling ine where to get information, and how to 

 nmko Bimjde instruments for experiments ? Where ran I got 

 information for a lecture on " The Atmosphere," and what oxperi- 

 monts could be made by ono who is nnabic to buy costly apparatus ? 

 —X. X. 



[215] — Moon's Brightness. — The sun's light striking moon more 

 obliquely, when near new moon, one would expect brightness per 

 unit of surface to be greater. Is this so?— C. T. B. [Onr corre- 

 spondent surely means less, not greater. It is theoretically less, 

 and actually less. — Ed.] 



[246] — Uarometer. — What is the mean height to mercury 

 barometer at the equator ? — C. T. B. [29'853 inches ; though I 

 should, for my own part, be disposed to doubt about the last decimal 

 figure. — Kn.] 



[2i7] — Warmth at Night. — I am a slight sufferer from chronic 

 asthma, accompanied, chiefly at night, with a few attacks of 

 coughing ; and friends have urged the use of gas, conveyed through 

 tubing to a stove filled with " asbestos," to warm the apartment. 

 Is it conducive, or not, to one's health to maintain the warm 

 temperature all night ? — J. M. J. 



ixfplteis to <Bnmt&, 



' [152]— "The Art of Klectro- Metallurgy," by Ci. Gore, LL.D., 

 F.R.S., (Longmans) 1877. I succeed perfectly where C. T. B. fail.s. 

 — W. Van Evs. 



[179]--FArRE AcruMur.ATOFR.— Other things being equal, the 

 power of Faure cells are to one another as the superficial area of 

 the plates ; but by using several plates in one cell, and coupling the 

 alternate ])lates together, there is some gain, inasmiich as you use 

 both sides of the plates. It a|>pears to me that it is erroneous to 

 call the Faure cell an accumulator. The Faure cell is, when charged, 

 a mere Voltaic cell ; and the action that goes on in the cell, when 

 discharging, is similar in its nature to that which takes place in an 

 ordinary Voltaic coll. The same remark applies to all secondary 

 batteries. — U. B. T. Strangwavs. 



[188] — Longevity of the Tortoise. — The late Professor G. 

 Pryme, of Cambridge, mentions having paid a visit at the palace of 

 the Bishop of (I think) Peterborough, and being there introduced 

 to a tortoise, said, by tradition, to be then 200 years old. Going 

 to the same i)Iaco some ton or twenty years later, he found that the 

 patriarch was defunct. The jiassage occurs in a very interesting 

 biography of the Professor, written by his daughter. — E. D. G. 



[191] — Animal LAKcrAGE. — Probably animals possess means by 

 which they express their feelings one to another, be those means 

 movement, looks, or even artifv.lation. Hut considering their social 

 state, we have no reason to expect that the Almighty endowed them 

 with powers of speech as the human race. The members of the 

 brute creation, living lives almost independent of each other, while the 

 very existence of the human race depends on the mutual help, and 

 therefore on the mutual intercourse of its members, what language 

 may exist between animals is of a kind vastly inferior to that 

 between man and man. But one finds, on studying the animal 

 world, that this language is more perfect in the higher than the 

 lower orders, some of the latter being entirely mute; the neighing 

 of horses and ponies, the cawing of rooks, the greeting of dogs, 

 and the language of birds being illustrative of the former, and the 

 lowing of kine and the silence of fishes of the latter. Apart from 

 the language which /Esop and La Fontaine put in the mouths of 

 animals, and the whistle which some other individual placed in the 

 mouth or the shell of the "Oyster of Drury-lane," we may conclude 

 that some inferior means of intercourse exist, and that to a greater 

 extent of perfection in the higher than the lower orders. — Herbert 

 H. Welt.er. 



[192]— Ice Aoe in Britain.— That an ico age or glacial epoch 

 haa existed in Great Britain, we may infer from the facts : that in 

 some parts the eminences are alK precipitous towai-ds the west, the 

 rasult of some powerful agent wearing away that side ; that in the 

 intervening v.alleys, boulder clay|(a blue clay, in which rounded and 

 waterworn iichblps are imbedded) is found ; that deep furrows 



across the country, and sirintions (acratchos) on the rocks, ar" i.li. 

 Her\'al'l'>, the Hiriationsand furrows being all parallel to theinf' ' 

 that all the eminences are rounded at their sumniita, the rr^i. 

 some powerful agent passing over thom. — Ukriikbt K. Wem.i 



[102] — IcR Age in Britain. — In answer to " Arnchnida," |. - 

 as lo what proofs exi.st, showing that there ever exintcd an i • 

 in Britain, reference to any geological work of any pretotj- 

 would have showed him the country fairly teems with proofs, from 

 the Thames to Cape Wrath. The three great witnesses of glacial 

 work are (I) the transportation of erratic blocks ; (2) the smiv.ili- 

 ing and scnitching of the valleys through which the gl 

 travelled"; and (3) the presence of arctic fossils in glacial di i 

 As typical instances, Staffordshire contains erratic blocks • 

 ported from the Cambrian group ; rocks from the Grampians :.ri.' 

 found GO and 100 miles south of those mountains; while in Wicklow 

 an immense block of granite is ]>crchcd up G50 ft. above sea- level, 

 and ten miles from tho nearest granite. Valley scratchings aro 

 typically cxliibited in the neighbourhood of Snowdon. .Vmong tho 

 arctic fossils are Trophon Clathratum, Aslarte horealig, end J'cctcn 

 Islundicus. — W. G. Rolfe. 



[195]— QiuK.siLVEB .vox-Poisonous. — It may interest "F.C.S." 

 to know that in former times liquid racrcnry was given in largo 

 quantities, even pounds, for obstruction of tho bowels. As to its 

 efficacy, I cannot speak. The fact is, that ordinary liquid mercury 

 passes tlirough the digestive tract without being absorbed, and, 

 therefore, without producing any effect upon the system. If. hr.w- 

 evcr, it be reduced to a state of very fine division (as is really the 

 case in grey powder, blue pill, and some other preparations of 

 mercury), it is absorbed, probably because its fine state of division 

 enables it to be easily converted into o.xide. — F. W. G. — [In parts of' 

 Ireland in former years a dose of small shot used to be given for a, 

 similar purpose. — Ed.] 



[105]— Quicksilver non-Poisonous.— For tho sake of F.C.S., I 

 quote the following words from " Taylor on Poisons " : — " Although 

 liquid mercurj- is not in itself poisonous, it is liable to be converted- 

 into poisonous compounds in the body," p. 360, 3rd Edition. — 1 

 Robert Macphekson. ^ 



[197] — Messrs. .1. & E. Hall's last designs are by far the best in, 

 the market, not only for efficiency, but on account of their simpU-, 

 city and the small space they occupy. — G.ay. , 



[200] — Le.ases. — " J.imes Gregg" should consult an actuary, orj 

 study Sii- Isaac Xewton's " Tables on the Value of Leases," or. 

 the modern " Tables " of Inwood, or both of these authorities. ' 



[200] — Leases. — To determine the value of a loose, evea' 

 when the conditions arc specified, is not always an easy matter. 

 To the following seemingly simple problem, I have received a, 

 score of answers, all varying. I would be glad of an authoritative; 

 solution. A. paj's for a fourteen years' lease, £1,050 ; the rent for 

 tho first ten years is to be £250, and £300 for the last four. At th« 

 end of ten years he agrees to sell the lease to B. at a proportionate 

 price to what it cost him. What is the amount B. must pay A. ? — •• 

 W. Cahill. 



G. M. T. 



[201] — Minima of Algol.- 



Feb. 



h. m. 

 16, 4 33 a.m. 

 19, 1 22 a.m. 

 21, 10 10 p.m. 

 •M, 6 59 p.m. 



March 11. 3 la.m. 

 ., 13, 11 53 p.m. 

 „ IG, 8 42 p.m. 



April 3, 



23, 



28, 8 



H. M. 



1 13 a.m; 

 10 24p.mj 

 3 17 a.m. 

 6a.iai< 

 55p.i 



Professor Pickering's observations, however, at Cambridge, U.85' 

 show that in 1880 the true time of minimum preceded that of tlw 

 cphemcris by about 37 minntes. " L." would do well, therefore, to 

 look out for the minima about three-quarters of an hour before tli6 

 times given above. Algol begins to diniinish about 1 hours hefoiB 

 tho actual minimum, and does not regain its full lustre till 5| honif 

 after the epoch of faintest light. Curiously enough, Algol has ft 

 companion at about 82" distance, which is also variable, but in soma 

 long period. It would take up too much space to answer " L.'a* 

 second ([ucry adequately. An east wind has sometimes a veljf 

 cvu'ious effect, rendering the discs of bright stars triangular, Mr 

 causing them to be apparently accompanied by a faint, close coM- 

 panitm. 1 found the latter effect very markedly visible on two 

 occasions in the early part of 1874. Webb had noticed the 

 thing. Perhaps the Editor would say if he has ever heard of t$t 

 " triangular " effect having been noticed in .\merica. — H. SadlsI^ 



[206] — Opium. — In chronic lead poisoning, the constipation, whiflll 

 is u.'snally very obstinate, is duo to a tonic, e.g., a continued COD' 

 traction of the muscular coats of the small intestine. If opium were 

 administered in such a case, it would act as a purgative, by c 

 coming this spasm. — RonERT Macphekson. 



[207] — Heat. — The hand can bo put into molten iron. Til 

 perspiration induced by fear provides a cushion of vapour, as il 

 spheroidal state. If tried too often tho experimenter has goJ 



