124 



♦ KNOWLEDGE 



[Dec. 9, 1881. 



funrtion. Tlioy nro ontiroly absent in tlip iingnlnta. Claviclos nro 

 very cimrnctcrislic of the lower vortebrntn, being well developed in 

 reptiles and fiKlies. — Oko. 



[10] — Cosir.»nATivK .\natomy of niiiiis .\su Animals.— In answer 

 to Query 1!) p. 80, the fiimihini. or " merry-thoiiglit," of birds 

 corresponds to the collrir-boneB, or clavicles, in man, wliicli, instead 

 of beinjif separately joined to the sternum, or breast-bone, are joined 

 toffethcr into a V-s'">I'ed nrcli of bone, the apex of which is 

 commonly attached to the Bternum by a ligament. The fonction of 

 the furcnluni, according to Owen, is to oppose the force which 

 tends to press the humeri or upper-winjf bones townnis the middle 

 lino during the downward stroke of the wing. — Mkdicis. 



[23] — Fatrk's .\r(UMi-r.ATOK. — "Nameless" will find some infor- 

 niution in regard to Fanre's accumulator in Nahirv, vol. 2i, p. OS, 

 " Storing Electricity j " and p. 238 " Fauro's Seconilary Battery." — 

 A. T. C. 



[23] — Fai-re Acci-MiT.ATOR. — A Faure accumulator may be made 

 as follows ; — Take lead foil such as used for iiutting on damp walls ; 

 cut the plates, leaving a long tongue at one corner — I made the 

 plates 4} X 2i inches, with a tongue 2 inches long and about i of an 

 inch wide ; ne.Tt take some flannel - 1 used common, at lOd. a yard ; 

 cut it in strips one inch more in length than twice the length of the 

 lead i)lates, and one inch wider than those plates ; then take some 

 blotting-paper and cut it into pieces, one inch each way larger than 

 thele.id plates; mi.T one pint of sulphuric acid, by measure, with 

 ten pints of water, by measure, and with this and some red lead, 

 make a paste ; now, paint over one strip of Hannel, on one side only, 

 with the paste, leaving a half-inch margin of clean flannel all round, 

 so that the painted part of the flannel will be exactly twice the 

 size of the lead plate ; paint over one of the lead plates on both 

 sides, keeping the tongue clean j lay it on the painted Hannel, and 

 riouble the flannel over it; lay this covered plate down on any 

 convenient board or [liece of glass. On this covered plate Lay one of 

 the pieces of blotting-paper, or, if the blotting-paper is not thick 

 and good, two pieces. I'reparc another plate of lead with the 

 flannel and red lead, as before ; place this on the top of the blotting- 

 paper, taking care that the tongue of this latter plate is on the 

 opposite side to the tongue of the first plate. Lay another piece or 

 pieces of blotting-paper, and so go on until you have a pile of as 

 many plates as will go easily into the jar or cell you intend to use. 

 See that the tongues of the alternate plates are on alternate sides 

 of the pile of plates, then tie the pile round loosely in a couple of 

 places with some paraffined twine ; pinch the tongues on one .side 

 together, and tho.se on the other side together, and attach termin.al 

 wires. Put the bundle of plates into the cell, fill up witli the acid 

 and water, and keep it fulir I have tried this plan, and found it 

 answer. — H. B. T. Strangeways. 



[26] — Training. — There are some facts, if one could collect 

 them, which seem to support " Oarsm.an's " question. Thus I 

 know of two or three bicycle riders who ride a hundred miles a day, 

 and yet who never taste animal food ; and, again, a teacher of 

 swimming who uses no animal food. The last few autumns a 

 number of gentlemen have set out for walking tours, and they 

 never use aninuil food, and yet get on very w^ell indeed, saying they 

 experience less thirst and less fatigue than if they eat meat, lic. — 

 T. R. Allin.son. 



[27] — Marriage DE.\Tn-nATE. — With reference to "Benedict's" 

 <|uery respecting the marriage death-rate, I may say, for Ida in- 

 formation, that the result of an estimation made, showed that a 

 number of married persons gave a mean death-rate of 6G"(3 ; and 

 <?f unmarried a mean of 62 OO.* I may also state that at the age 

 of 15 to 20 the mortality is increased considerably, especially 

 among women — the majority of deaths resulting from consumption 

 jmd childbirth. A greater proportional number of deaths occur 

 among those who marry at an early age. — Michael W. Reynolds. 

 rRest of letter not strictly ail rciu.— Ki).] 



[27] — Marriage and the Death-rate.— I refer " Benedict " to 

 the follMwjng extract from the Times (Weekly Edition), Febuary 

 14, 1879 :— 



" It has been shown from statistics that in general, married 

 people have a less mortality than the unmarried or widowed. 

 .\mong facts indicating the relation between marriage and physical 

 health, it has been proved by M. Janssens, of Brussels, that at all 

 ages widowers are about twice as liable to phthisis as other men, 

 but that married jicople are generally more liable to this disease 

 than celibates. This law is constant for women ; for men it holds 

 good only before 25 years of age and after to. Such facts and 

 their meaning are discussed by M. Bertillon in a recent pa|ier on 

 tbe inflnenco of the family state on morals. Not only do married 

 people die less than others, but they show less tendency to suicide, 



to montnl derangement, to asBixsination, to theft, and other like 

 evils or crimes. . . ." 



And the extract goes on to show that this is probably owing to the 

 influence of children. — B. J. 



[27] — ErpECTs OF Makriagk on the Death-rate. — Dr. Bertillon, 

 a French uttvattt, some two or three years ago wrote an essay on 

 " Nuptiality, or the Conjunctive Attraction of Human Couples." 

 By comparing the mortality statistics of cverj- countrj- in Europe, 

 he shows that, without exception, marriage is condacive to 

 longevity. Uo arrives at the conclusion that a bachelor of 25 is 

 not a better life than a married man of 15. French bills of mor- 

 tality show that the annual death-rate among married men 

 between 20 and 25 is rather under 10 per 1,000, ond for bachelors of 

 the same age, 16 per 1,000. For Paris itself the difference i.s still 

 greater. Between 30 and 35 years of age the mortality is 69 per 

 cent, greater among bachelors than among married men. Space 

 will not permit further quotations from this interesting essay, bnt 

 a more complete summary of Dr. Bertillon's conclusions " Bene- 

 dict" may find in the Lancet for May 31, 1879. — Mewcis. 



[28] — Stone on Rolling Wheels. — If the stone was poised 

 exactly in the centre of the wheels, it would then be carried forwanl 

 75 in. for each revolution, and the relative position of the stone and 

 wheels is not altered. But, as the stone rests on the circumference 

 of the wheels, it receives a motion from the revolution, and the 

 part which rested on the wheels would be 75 in. beyond them for 

 each revolution ; and the forward motion of the wheel being 75 in., 

 therefore the stone has advanced loOin. It has travelled the same 

 distance as a spot on the circumference of the wheels, which de- 

 scribes a cycloid for each revolution, and is equal in length to 



* There is some mistake about this statement. — Ei). 



double the circumference. I beg to inclose drawing, where A is 

 commencement of a revolution, and B the end. — W. Stevens. 



[28] — Stone on Rolling Wheels. — "Queensland's" "mathe- 

 matical friend" is quite correct in saying the stone advances 150 in. 

 for every 75 in. advance of the rollers. ••Queensland," or any one 

 else, may easily convince himself of the accuracy of the statement 

 by a few minutes' experimenting with a two-foot-rule and an oflic© 

 ruler.— E. H. R. 



[37] — "Vestiges of Cre.a.tion."^I have seen it stated that the 

 late Dr. David Page, the geologist, was the author of this book. It 

 has also been attributed to Mr. Robert Chambers. Both may have 

 been concerned in it, as Dr. Page was for a long time connected 

 with Chambers's Journal. I think Lieut. -Col. W. A. Ross announced 

 in the columns of the English Mechanic^ some time ago, that he 

 believed, and could prove, the author to be Sir Charles Lyell.— J. A. 

 We.st«ooi) Oliver. 



[37] — Ve.'^tiges of Creation. — This book was written by the late 

 Dr. Robert Chambers, of Edinburgh. It foreshadowed, in softie 

 measure, the speculations of Darwin on the origin of new species 

 through the nioditication of the old, as opposed to the doctrine of 

 their " special creation." It advanced further than Lamarck ; but 

 Dr. Chambers' ideas were necessarily crude, for lack of the know- 

 ledge of later days, when compared with the certainties of motlem 

 evolution, which is founded on evidence derived from the develop- 

 ment, structure, and distribution of animals and plants, as well as 

 from their fossil history. " S. S. S. S." should read Darwin in pre- 

 ference to the "Vestiges," which possess, nowadays, more of a his- 

 torical than a scientific interest. — Andrew Wilson. 



[37] — Vestiges of Che.\tion. — This work was published 

 anonj-mously. Some — the majority — attribute it to Chambers, 

 others to Sir C. Iivell. The subject was discussed recently in the 

 columns of the Kn'jlish Stechanic. I should advise "S. S. S. S." to 

 read it bv all means, and mark, learn, and inwardly digest it. — 

 W. G. Ro"lfe. 



[38] — Neitine. — One satellite of Neptune has been discovered 

 by Lassell, period 5d. 21 h. 8 in., at a distance of 220,000 m. from 

 the primarj-. — W. G. Rolfe. 



[Let. 48] — CHE.4P Microscope and Telfjmtope. — If your correspon- 

 dent " Twenty " is not disposed to spend more than £5 on each of the 

 aliove, he must restrict himself to a monocular microscope, and I 

 should advise him to procuro one of the so-called medical forms 

 made by Swift, Beck, Baker, and several others. It is rather in- 

 vidious making a selection from the several makers of low-priced 

 microscopes, but 1 am bound to say that of the instruments which 

 have come under my notice lately. Swift's are the best value for the 

 money, taking into account the appearance and general qualities of 



