♦ KNOWLEDGE 



185 



A CALCULATION-. 

 „„f ^°^i~'^'!? question of Pj-ramns, in yonr number of Jane 23 is 

 tho\d™f/ ^^f^'S,H« ^T not say under what conditions 

 their sILerTptTons"^"'''""' '^°" '°"^ '""^ '"^""'^^^ ^'^'-''^ 

 thft^'th^"""" ""f '"^^^"'^'^^ ^"-e ™ade as soon as £500 is in hand, and 

 rn^PnT.. ^^"™«^]f '^I'-al monthly payments, the first monthly 

 a^dTh»f fh k"" *'^'': """""^^ ''"<''■ "^-^ 'J'^fe «f the advance, 



monthlv nnf .T'^i'^'^'Sf 1"""= subscribing £12 per annum, payable 

 S Thv7' f ^ 2'^„'^^^<' received advances, then the number 



of advances for each of 19 years will be respectively- 



12 13 U 16 17 18 



19 22 23 25 26 30 



'^if hfrpl^T? "^^^"^ "^"'^- '^'"'^^l monthlf subscription 

 Tonev «Hn^r f " ^T" '"°°*i'' '""^or, during which sufficient 



^i:Sn::l'i::zjtiiTXr '"' ^^-'^ ^'''^'"«- «•'--- -^'^ 



AJouTadva^nc'eV'' !"' °.' ''!:'"^' '"°"'>^ "''" ^'^^^ '^^ ^ 

 Returned 



£250,000 

 135,9 



Amount in hand 



£115,000 



thril" ^;'bsoriptions for 230 months. The calculations leacbn.. to 



be^^rimewWlIZrT'';/'^"'^"™'^' "'"' '" ^^° t''^'". 1^°' 



Walwo"": Julilo^^&i"^' "°' "°" '^°°"^ """rWA^KK^M. 



BEEATHING THROUGH THE NOSE-TURKISH TOBACCO. 



[510]— Mr. Hume in his letter (Xo. 444 r 

 sity of breathing through the nostrils, and 

 not quite correct in 



be 



9) shows the neces- 



^SMn^:^crT7r""^¥'^™"^^^^'-3a-^-^he 

 cn^to^^t ^ ./ tobacco-smote upon me, as it has always been my 

 ^!nl^ '"breath m the manner he advocates, and find it difiicultto 

 Tl "f m" °P<"^V°° '." ""y °tl>^'- ^ay- Again, I cannot cor^ 

 fnl.^ f '■•■A™'"'°P'r°*'"" *'"^ ""^-^ "'■'^ ««a filter to the 

 }TZff%' ^t^T"' '^"""^^ '^"'^ "'■ ""y «">■■<! substance would 

 he «?,>.! ™ that way, yet anything of a gaseous nature would 

 Portion ofbrfn"^ as common air. It is quite probable that a 

 portion of the fume would condense within the nasal or.-an • but 

 h.s would only ?...,„ the evil, and not eradicate it. Whatever i 

 o fi t7.Hor% / ^ soothmg effect of tobacco-smoke, it is not due 

 to filtration; if it were so, there would bo no need to smoke as 

 keeping the mouth closed would be sufficient ' 



r at°'' a'littrvr"*'^""* ^^'''- t*^' P^"^ ondeavonrs to show that 

 forThP V ■!- T "\ '■"S'''"'' *° *^^ *°''"^«° °'«"1 by the Turks 



for the ^arglle. I am always ready to be convinced that I am 



^7iZ^'^,7 \l'"^ '^''' "^? experience of a majority is contrary t" 

 mine ; but for the present I will persist in what I have stated in 

 my former letter. And I am not alone in my behef!as severa" 

 noxlousTomht ';i"f '" Constantinople had warned me kgainst tt 

 noxious Tombek, before I tried the experiment mvself. Tli^ophilo 

 Gautier " ^'^ "Constantinople of to-day," says, "-Ihat the Tonibcld 

 ■s of a darker colour than the other kind.,, and is so strong hat iJ 

 cannot be smoked until after two or three washings " Per aps I 

 had the misfortune to make the trial upon im-washed Ton.bekP or 

 .'nfiTof ■'' It' c"' ^,T^??^'= ^''^^ P'^y-' "- " iitt'e ol^oi'the 

 ^ onr ^ r w , .7" Constant Reader" recommends me to 



try our English forms of tobacco. Docs he think it probable that I 



well accustomed 

 may say that 



Tnrk ::."„"" ""'■■'; "'x' '"'",.'"; ""tamed in England or abroad. 'Ti" 

 guarantee to find as much solace in it as the Turk does in his 

 ^.r.T' uV^" "''Slf'^'od opportunities!" says my friend. I 

 wonder has he never ncgected any himself? His belief that the 

 Turks are temperate .n all things, seems to ignore (or neglect) the" 

 W. 0. PBOS.SEB, F.C.S. 



am convinced that there is nothing to be compared with mathe- 

 matics, say, an hour's tussle with geometrical problems two or three 

 times a day. In this way I have astonished myself with the cures 

 1 have effected. 



Above all things, avoid stryclinia (or nux vomica) and quinine, 

 and the like. I have known even stomachic tonics, such as 

 chamomile, do much harm. jj g 



[We quite agree with II. S. about the mind-quieting qualitios'of 

 mathematics ; but mathematical studies are not to the taste of all. 

 and would only worry many. They are in my own case wonderful 

 pain-soothers. The toughest paits of my treatise on Cycloidal 

 Geometry were ^-ritten when I was suffering intense pain from 

 renal calculus, to which until the last few years I was much 

 subject. — En.] 



ica^^^-'~'^^ '!tiotation of your correspondent, W. M. M (letter 

 408, p 117), very accurately describes a trouble from which I 

 suffered terribly five or six years ago, but of which I completely 

 cured myself. In my case it took the form of doubts as to the 

 safety of deeds, letters, Ac, which were in my care and could not 

 be replaced if lost, as to the correctness of technical and other 

 details in documents prepared by me, as to whether I had really 

 turned off the gas in my bedroom at night, and a number of similar 

 matters, such as a man in sound mental health attends to daily 

 1 them any cause for anxiety or worry. In each 

 doubt, any neglect or omission might have led to 

 serious con.sequences, and the thought of the possibility of these 

 resul s following weighed upon me so that I at length became quite 

 unable to accept the testimony of my senses to' the fact that I had 

 done what I intended to do in any matter of importance. I 

 attribute the mischief solely to "nervousness" arising from ex- 

 cessive brain labour. My professional work and many of my every- 

 day social duties were fast becoming an unbearable burden, and" I 

 telt that I had before me the prospect of failure in life, when, upon 

 the advice of a friend, I adopted a simple expedient which led to my 

 cure. 1 promised him and myself that on a certain day I would do 

 everything I had to do carefully, once for all, and then absolutely 

 leave it, let the consequences be what they would. I did so on that 

 day, on the next, and so on, reporting to my friend periodically that 

 1 had faithfully kept my promise. At first I had an arduous 

 struggle but 1 felt it was then or never, and I persevered ; nothing 

 happened to me and I gradually gained control of mvself, and al 

 last 1 was completely free from my fetters. '_ 



I hope my experience may be useful to others. Mintaka 



without finding 

 of such cases, 



w M ^r^ ! .^Tc"! '"'""''■°- °°<=^ be think it pr 

 would attempt a trial of Tombeki, if I was not already wel 

 to the use of English tobacco? For his information 1 1 



kinds oVfhI°j°'^!,P?''''''l°^™°'"■'''?• """^ bave usednearly „.. 

 kinds of the weed that can be obtained in England or abroad. The 



existence of Harems. 



BRAIN TROUBLES. 

 for^the-''Mit^,''''T^ ""fr r'r*''' "° '="'•'' mentioned in your journal 

 uLn this ,n^- '^r }'" r'''"" '■"'■'' J-^^'y "-'"'^'"^ attention in it. 

 ac^stomed tf •'"'■''?'" ^ ""F ''""'^ "•'"' ''•'tbority, as I am well 

 accustomed to various forms of brain trouble. 



health'iflot; !t!;?l ri' '"P°^'«"' indications are to restore the 

 nealt ., it lo^ and to keep the bowels faiily loose. It is a eood 

 o on "dr""" "='".'«'' ."<^^' 'be skin throughout the year. A variety 

 of out-door exercise IS essential. But from personal experience I 



BICYCLES. 

 [513]— I am not sure whether the subject of " bicycles " is ranch 

 in yonr Ime as the Editor of Knowledge ; but as the matter I write 

 of possesses a mechanical interest, you will, I doubt not, whether 

 you insert my letter or not, give it your usual courteous con- 

 sideration, and say whether you think my ideas correct. 



In the best bicycles both wheels are mounted on ball bearings as 

 these run more easily. But in machines of a commoner kind, the 

 front wheel only has ball bearings, while the hind one is mounted 

 on cone bearings. Cone bearings are much stiffcr than balls • that 

 IS, there is more friction. Now this. Sir, is the point to which I 

 wish to draw your attention. The hind wheel of any onlinary 

 o4 lu. bicycle is never less than about 18 in. Hence "it rt-volvcs 

 three times as fast as the front wheel, and, other condiiions being 

 the same, would have three times the friction at its bearings. 

 I'rom this it would seem that the order of things with regard to tho 

 bearings should be reversed, and Ihat tho hind wheel should have 

 ball bearings, and if we must have cones at all thev should lx> in 

 tront. I have never put tho case to anyone in this light, but I have 

 more than once asked why ball bearings are put on the front whwl 

 rntlier than on the other. Tho answer I received was, that there is 

 more weight on the front than on tho hind wheel. This I admit, 

 but I do not think there is such a diffeivnco in pressure on tho 

 bearings as will justify anyone in asserting that tho front whev-l has 

 more frict ion than I he hind one. The frict ion due to pnvssure varies 

 as the pnssurc. \\c can assign to each wheel its share of tho 

 pressure. 



I measured a 54-in. roadster to-day. The distance between tho 

 centres of wheels was 36 in., while tho saddle was only 11 in. 

 behind the centre of tho front wheel. Ucnee the pressures on tho 

 wheels are as 25: 11, or very little moi-e than 2 to 1. And since 

 this 13 not so groat as the relation between the friction due to 

 revolution of the wheels, I think it does not justify the practice of 

 putting ball bearings in the front instead of in the hind wheel 



Having stated my ca.so. I ahouM 1h> gin.l. Mr. Editor, if you would 

 kindly give ine your opinion, and if I nm in error, show me tho 

 "K .vou beforehand for the trouble you liavo taken in 



reading my letter, I am 



Tnos. B. Walkkb. 



