332 



♦ KNOWLEDGE ♦ 



[Oct. 13, 1882. 



vssurL- a!i\nhoro, and the girl wlio readies wonmii- 



I ion of a figure with its rouiul and taper 



I woll-developed chest. SUo will bo 



: and stooping gait which is tho natural 



. ; of stays imperfectly or injudiciously 



»..;> and will be necessary to restrain, limit and 



• figure. Without aid nature seldom forms a good 



i early correction, instead of violent and sudden 



lii.ity, is the way to oehievo success — no evil effects 



lie. Parents should sec to this matter, and take as 



the pliyeieul growth and proportion of ligure of 



they do iu their mental development. 



f the corset, tho degree of comfort with which it 



' the tost of utility. Korly care and judicious 



:. every case succeed in attaining elegance and 



..:ii. ALFKED CUAOWICK, U.D. 



Lettebs is Ttpf..— Physiological Experiment, by Z. ; Talking 

 ' .nary, iic, by Charles L. Cone; Dr. Hunter's Experiments, by 

 M;ithilde Van Kvs ; Coincidences, by A. H. W. ; Lapidaries and 

 Decoj.tiun. l.v H. M. W.; Wollaston & Fairy Rings, by A. W. 

 Po>vurd ; The Fifteen Puzzle, by A. B. ; Flint Jack, by E. T. C. 

 \y. ; Long 'Iricycle Hide, by J. F. P. ; Spiritualism, by E. P. W. 



gnstotrs to Coricsponlifnts. 



BJ /or tit Editor rtqttiring early attmlion thould reach tht 

 Saturday ;/r»«</ii.j the cnrrrnl M.n» o/ KsoWLIDOl, tht 



' K-kick eompeh h« to go to prei» tarty in thf tcerk. 



'Utyn.—l. yo queitiont a»k\vg Jor tcimtifie information 



•■ tkt pott. '1 Lttttrt tent to t\r Editor for eorrffpotidtiita 

 r can tk* nan/f or addreettt of eorretpondent* be i/icen in 

 "1. 3. Corrtnxmdrnlt etiould write on onr tide o'ly <j/- the 



I on a irparale leaf 4. Each letter ihuuld hare a title, and 

 uld 6e wuid* to it* numbtr, the fagt on which it 



NjnrroN Croslaxd. ^\liat Professor Smyth says is in perfect 

 ai.'rteni.nt with what I said. Obi-ervc, ho says, "moderates tho 

 eicesses, ' meaning that the water vapour causes the difference 

 betwceii tl.c temperature of the day and night to be less ; it docs 

 this by very slightly diminishing the heat received from tho sun 

 (scarcely to any perceptible degree in fact), while it very largely 

 diminishes the radiation from tho earth at night — in fact most 

 of the time.— C. C. C. C. Your method of dealing with sums 

 in doable rule of three is good, but wo have not space for it. I 

 Icd'jw of a way of putting the matter which I have found very 

 easily understood. It will occupy less space than yours, and I may 

 pretently give a short note about it.— Sta.nlev liAi'.DWix. Some of 

 the accounts of fairy rings given by correspondents caimot bo 

 ciplaintd in that woy— that is, that they grow over the roots or 

 stumps of trees.— E. j'. Hollow av. Glad you are ple.ised.— E. C. D. 

 Do not know which would be called tho best books of geometrical 

 riders.' You will find the names of several books on «(|uaring tho 

 circle and trisecting the triangle in Dc Morgan's " Budget of Para- 

 doxes." — Wm. Wood, J ink. I should have said a few weeks ago, 

 "Would that there were more readers like you;" but since 1 asked 

 for opinions aI>out the weather charts, I have received so many 

 kind and conniderato letters, that I now quite recognise wliat a 

 %-erjr small jirofortion of readers the grumblers represented. — 

 An.-TAiXf;t I so fully recognise the misery produced by excessive 

 drinkii.g, and I know so well bow many there arc who cannot 

 abktain from eircBS, and therefore should abstain altogether from 

 "I"'' " ■■ ' ■ tiiiiot but >ynipathise with yonr views. But I 

 ' ■ ■ ' ■ 'o » ho have not the slightest temptation to 



< li.Mlcmte allowance should be expected to give 



"• 'to your theory that everyone ought to bo a 



liii." i.r I,. ,.,», i>t the weaker seek safety in such resonrccs, and 

 be cornoiit to let us go on in our own way. In fact, lot the Blue 

 UiMx,n !/<• regarded aa tho budge of those who cannot trust them- 

 I"-;-. '-. !• N usually undcrstoo<l, I find, to bo worn only by 

 ^' ' which is rather hard on the Bluc-Kibbonists. — 



'■' was, ten years ago, my own experience, 

 ' ;■ found reason to agree with my "learned 



'■ The circular halo round the sun is caused by 



'■ f ite in the ujiitcr air; it is, therefore, not 



I rriinbow. — J. M. 6. Do not know the price or 



I .orks yon name. — G. Glasgow. (1.) The star 



:, IS of the second magnitude. (2.) The map of 

 :i -.'.rj' inaccurate ; a bright star between the Pole-star 

 . irdians lias no exist<;nce a* such in the hcavcni. Then 

 rc-ally belonging to Draco are shown as belonging to the 



Little Bear. (3.) I think the Nebula in Andromeda may as well bo 

 shown, though there is no absolute necessity for so doing. (4.) Tho 

 stars yon name r, fi 15, nnd r -are all of tho fifth magnitude. — 

 Ploni Almom informs " Con-siniit Header" that there is iv Micro- 

 scopical Society iu Liverpool, and that Mr. Thompson, of 0, Lord- 

 street, might bo able to tell him tho Seorotnry's name. Best book 

 probably Nicholson's, but Cornish, of Piccadilly, and Owens 

 College, Manchester, would send him a list to choose from. 

 Uo further recommends Stanley Jovons' olemontary book on 

 Logic. I intended my reply to " T. A." to mean only that in 

 several explosions there has been tho out-rush to which ho 

 hud referred. — TnoMAS Kimber. Timo-difforonces betwoon various 

 jilaces seem so easily dealt with when the longitude is known, 

 that I cannot see the advantage of any of tho plans you mention. 

 — C. Francis. (1.) I do not know of any scent that will " make 

 a person light," nor of any that will " sot him right when ho has 

 been made light; " I cannot say that 1 quite know what you mean, 

 either. (2.) Doubtless some correspondent will toll you a way of 

 making silk air-tight. — H. F. Tho InleUcctual Obacrver is not now 

 iu existence, — worse luck. It was one of the very best scienco 

 magazines ever published. — G. Caird desires infoniiutiou about 

 Boyal Exhibitions at tho Normal School of Scienco. Ho asks if 

 Todhunter's Trigonometry for Beginners is sullicient for Honours 

 third stage or for ordinary third stage. — Willlvm Davies. Tho 

 magnets would keep tho pendulum in motion, at least for a time ; 

 friction would soon bring it to rest. — Harvard GRAnAHE points out 

 that Mr. Acfcroyd's results, instead of being in opposition to those in 

 the Chemical News, arc in perfect agreement with them, and, in 

 fact, might bo deduced from them. In one case there is a scale of 

 colour reflected from substances at different tomjieratures, while in 

 tho other we have a scale given out by bodies raised to temperatures 

 at which they become luminous. — A. J. Haynes desires information 

 about American universities. In rejily to his query about tho 

 absence of mathematics, we note that no loss than eight sections of 

 the articles on the Differential Calculus aro now in tho j)rintcr's 

 hands; four are in type. — E. C. H. Your questions aro worthy of 

 a fuller notice than wo could give you in these short answers. Will 

 try to deal with them soon. — And. Aitkkn. Many thanks for your 

 suggestions, with which I quite agree. As to the UilTerential Calculus, 

 I think Todhunter's as good a book of its kind as vou can readily Use. 

 — E. T. C. W. (1.) Vol. II. will close, as you say, with No. 61. 

 (2.) Pages v. (No. 33), vi. (No. 43) not to bo bound up. (3.) No 

 jiarticular results followed from tho Hippocampus controversy; 

 both tho disputants considered that they had tho host of it. (4.) 

 I have not been siiecially informed on tho subject, but — ot a 

 venture — I should say that when tho moon was commanded to 

 stand still over Ajalon by Joshua, this did not '■ make any differ- 

 once in its motion," and the moon could and did " turn exactly 

 tho same face towards tho earth before and after." I was not 

 there at tho time, however, ami should not care to speak 

 positively as to what did or did not happen in that encounter. 

 Can you, in turn, tell me whether Scamander flowed as before 

 after Vulcan " breathed " that " fiery blast around," which caused 

 tho river to " rear his languid head," and appeal, " short panting," 

 for a rest ? But possibly you were not present on that occasion. — 

 S. J. There is ample room for you in tho waste-paper basket; send 

 some more. — B. M. You could not find any cyclopiedia without 

 omissions or imperfections. It would be unfair to note those of ono 

 in particular.— Thikleb. If you insist that (T'-O (or, if you like it 

 bettor, that (r' =0), there is an end of tho matter. You begin with 

 a mistake and naturally obtain an erroneous result, which you call a 

 sophism. You oan explain it your own way, — with great ease, I 

 should imagine.— A P. S. Thanks : this world enough for tho 

 present; the " occult" does not specially interest mo. — Hallvards. 

 Your letter would raise discussion which would bo out of ])lace in 

 Knowleikik. — K. Lkigii. Thanks, but correspondents prefer we 

 should make no attempt at weather-charting in any way. — 

 J. Stack. I agree with you that medical aid which 

 simply keeps life in a used-up and depraved body is not an 

 unmixed Idessing. But your views might bo misunderstood, and 

 BO offend.^J. J. BfliiE. The elastic recoil would suflico if you 

 breathed out into a jierfectly elastic bag; but how is tho energy in 

 the moving air, as it leaves tho lungs, to bring air back again ? — 

 J. B. Possibly some correspondent can tell you the best wuy of 

 destroying crickets. Tho following acted well " in our house at 

 home," some three years back ; — A careless servant (first provide 

 your careless servant)' loft two or thrco used tins which had once 

 held condensed milk, ond wore still wot nnd sticky, inside tho 

 kitchen fender. Next rooming they were full of cockroaches and 

 crickets, which were forthwith consigned to a watery (boiling 

 watery) grave. Next night no insects aiijwared on tho scene. 

 Soon after some young ones began to bo seen, which were caught 

 in like manner. For months afterwards tho kitchen was clear 

 of these nuisances. If you should try tho method and it succeeds, 



