MARcn 24, 1882.] 



• KNOWLEDGE ♦ 



457 



opposed to the methods of education prescribed by "Susan G." (in 



KsnwLEDGK of Dec. 2), who has spoiled an otherwise good argument, 



-I far as it goes, by her singular advocacy of "physical force." 



I'hyaical force is ceiisinf) to do the world's work; thought is be- 



iiiing everywhere more and more the mighty motive-power. 



' 'n the great underlying principles of nature are fully realised, 



1 the possibilities which reside in the being of man, as nature's 



It representative, the freedom and equality of the sexes will no 



^I'r even bo questioned. By forcing his way into the realm of 



11,'ht, man has really opened the door for the attainment of 



ii.'Cted womanhood. Si'SAN E. Gay. 



VENTILATION BY UPEN FIREPLACES. 



:!51] — I maintain, and can prove, that the "fire-hole" which 



Mr Mattieu Williams wants to stop up, admits of a room being 



!t^ uniformly warm and well ventilated at a small cost, better 



'! any other means known at present. But it is essential that 



room have a direct air-supply. If this be delivered into the 



■M by a tube or tubes of not less than 48 square inches sectional 



'. at, or near to, the mantel, and directed towards the ceiling, 



"fire-hole" will draw from the upper part of the room, the 



I I upants will have a continuous supply of fresh air, and the floor 



will 1)0 warm. There should be the means of warming the direct 



iT-supply ; several forms of open gi-ate are made which do this. 



'■■ the winter there is a clamour for warmth, but during the gi*eater 



r- of the year it is ventilation that is wanted. F. Li.oyp. 



So far as my experience goes, we suffer much more from bad 



: ilation in winter than when the weather is tolerablv warm. — 



THE PHYSICAL APPEARANCE OF SATURN. 



:i.52] — In your " Otlier Worlds than Ours " yon show, by the 



l-iit changes in Jupiter's cloud-belts, that that planet is most 



: ably a glowing mass, bubbling and seething with the intensity 



■ l.c primeval fires. You state in the same work that tlie belts 



^ iturn resemble those of Jupiter in general shape and in colour, 



i also that his belts change in aspect much as Jupiter's have been 



■rved to do. The great diversity in the appearance of Jupiter's 



sin numerous drawings seems to quite bear out your conclusions 



I . that planet. But I am anxious for further information before 



in hold your views respecting Saturn with the same confidence. 



'nn'iit every picture of the latter planet (including the exquisite 



Miiiig in your " Other Worlds") represents it with belts almost 



■ on in outline as if they had been turned in a lathe — an appoar- 



' not at first sight, at all events, indicative of violent atmosphe- 



' disturbances. In " Guillemin's " Heavens," however, there is 



iwing of Saturn with irregular belts, as seen by Bond in 1848, 



if the majority of the pictures of the planet possessed this 



rioteristic, as those of Jupiter do, I should feel no dilliculty in 



;aiug your conclusions about Saturn's condition. If you would 



lily clear up this matter for me, I am sure many of your readers 



V.-, mid be greatly interested. More Light. 



liomembering that Saturn is so much farther away than Jupiter, 



! -0 much more faintly illuminated, it is not surprising that the 



• telescope which shows irregularities in Jupiter's belts will 



il none in Saturn's. Speaking roughly-, we receive from a 



-ipiare mile near centre of Saturn's visible surface only about a 



I sixteenth of the h'ght we receive from a similar portion of Jupiter's. 



' But with high powers, not only are in'egularities seen, bnt rapid 



li inges have been witnessed, in the Satuniian belts. — Ed.] 



A NEW FORM OF ELECTRICAL ACCUMULATOR. 



[353] — Seeing an account of Fauro's Accumulator in this journal 

 (No. 8, page 15S), perhaps the following will not be uninteresting 

 to the readers of Knowledge : — 



Mr. Henry Sutton, of Ballarat, Victoria, has invented a now 

 form of electrical accumulator, consisting of a copper cell contain- 

 ing an acid solution of sulphate of copper (blue stone), in which 

 is immersed a plate of amalgamated lead, but not in contact with 

 the copper. On connecting the accumulator with a battery or 

 dynamo-electric machine, the copper solution is decomposed, 

 metallic copper being deposited on the copper cell, and the lead 

 plate is coated with peroxide of lead. When the solution becomes 

 colourless, the cell is ready for use. 



This cell is much smaller than a Faure or Plante cell of the same 

 power, is very constant, and the inventor has generously placed it 

 at the disposal of the scientific world free from all patent rights. 



A cell, 6 inches square and 2 inches wide, was exhibited Ijy Mr. 

 E. Davis, at the Liverpool Chemists' Association, Feb. 2, which 



heated to whiteness and finally fused a thin platinum wire, and 

 also worked a small Ruhnikorff's coil. (ViJe Phannaceutical 

 Journal.) H. P. CooPBS. 



THE RADIOMETER. 



[354] — Your correspondent, Mr. Gladstone (298), is, apparently, 

 not aware that the motion of the radiometer is duo to rays of heat, 

 not light. This was, I believe, first noticed by Mr. Prcece, and may 

 be proved by the following experiments ; — 



1. Hold a sheet of thin white note-paper between the light and 

 radiometer ; the paper, being transparent, allows light to pass but 

 cuts off the rays of heat ; no movement ensues. 



2. 'J'ake a sheet of very thin ebonite, which will stop every ray of 

 light, but, being diathermanous, allows the heat to pass, and the 

 radiometer moves round merrily. 



Other similar experiments may be made by interposing a glass 

 trough filled with sodium dissolved in bisulphide of carbon, and 

 another with alum in water. 



Wimbledon. Wir.T.iAM InviNG Page. 



SOCIAL INFLUENCE OF WOMAN (273). 

 [355] — " E. Burke " says, " Name a nation where women are 

 debarred from social influence, and you have named one which is 

 proportionately backward in liberty and knowledge." I take up 

 the challenge, thus : I suppose that " E. Burke " will allow that, in 

 respect alike of "liberty" and of "knowledge," the Athenians of 

 old excelled their rivals, the Spartans. Vet Professor Mahaffy, in 

 his " Primer of Greek Antiquities," writes as follows (p. 45) : — 

 " We do not find that any Greek valued her high qualities for these 

 important duties rightly, except the Spartans. For among them 

 alone we find the mistress of the house a person of real importance, 

 appearing when she chooses in public, and even offering an opinion 

 which is respected on public affairs. In cultivated Athens, on the 

 contrary, she was only taught spinning and cooking, and what rude 

 medicine might be wanting for the treatment of her household in 

 trifling illness. . . . Thus the liberty of women varied from a 

 freedom as great as need be in Sparta, to a life of seclusion and 

 neglect at Athens." E. I). Girdt.kstone. 



THE LANK YANK. 



[356] — Mr. Mattien Williams, in his paper on " The Air of 

 Stove-heated Rooms," in your issue of the 3rd instant, gives it as 

 his opinion that " the lank and slirivolled appearance of the typical 

 Yankee " is due to the dryness of his native climate, and to the 

 further dessication (or rather increase of capacity for the absorp- 

 tion of water-vapour) of the air caused by stove-heating. I should 

 like to know how he reconciles with this theory the generally well- 

 favoured and rosy appearance of the Canadians. Surely their 

 climate cannot be considered so much more humid than that of the 

 Y'ankee, with his great extent of seaboard, as to account for their 

 marked difference in looks. He seems, too, to have overlooked the 

 fact that in American and Canadian houses heated by stoves there 

 is almost universally a steam-generator of some sort (usually a pan 

 of water on the stove), which counteracts to a great extent the 

 avidity of the air for water. Out of doors, too, the temperature 

 being so low (often below zero), the ca]>acity of the air for water 

 must be very small, and the dessicating effect scarcely perceptible. 



Would it not bo much more natural to account for " the lean and 

 shrivelled aspect " of the Y'ankee by reference to his habit of life 

 and, specially, of feeding, so very different from the roast beef and 

 plum pudding of the Britisher ; while, on the other hand, the 

 Canadians, who still keep to the English way of liWng, have not 

 lost the jolly and comfortable appearance of their forefathers. 



I might add, too, that the Swiss and Germans, whoso houses arc 

 nearly all stove-heated, and without the advantage of steam (for I 

 never remember seeing water-pans on their stoves), are by no 

 means a meagre or lanky race. Canadensis. 



THE CALIGRAPH. 



[357] — I can furnish " Clericus " with any information he may 

 desire regarding an improved type-writer kno%vn .as the Caligraph, 

 v/ith which, by the way, a recent communication of mine to Mathe- 

 matical Queries in Knowledge was written.— W. W. Beman. 



Anne Arbor, Mich., U.S.A., Feb. 23, 1882. 



EYESIGHT OF DOGS. 

 [358] — I had not the good fortune to be a subscribor when tho 

 article in Knowledge on the noar-sightedness of dogs appeared, 

 but I have observed this peculiarity. A month ago my brother and 



