286 



• KNOWLEDGE • 



[Feb. 3, 1882. 



vill further suppose tlmt the air was fully saturntofl with 

 i'|u<-ouH vnpour, !.'•., just in the conilitioo ot which NOino of 

 it« watt-r ini({ht Ikj coikU-iirciI. Such coiidonsation, how- 

 ■ viT, can only take place liy cooling the air l«elow .12^ ami 

 iiiilesK the wiilU or ceiling or furnitiire are capable of 

 doing this they cannot receive any moisture due to such 

 condensation, or, in other words, they must fall lielow .'{"J 

 in order to odtoin it by cooling the lilni in contact with 

 them. Of course Dr. Siemens will not a.ssert tlmt the 

 stoves or Kteam-pipe.K (enclosing the steam, of course), or 

 the hot air or hot water j " .< will hm-.i- ihi' absolute tem- 

 per.ature of the walls by heating th<' air in the room. 



I!ut if the air is heated more rapidly than are the walls, 

 ..c,, the T'liilivc temperature of tln'se will be lower. Will 

 condensation of moisture l/ien follow, as L)r. Siemens 

 athrms 1 Let us suppose that the air of the room is raised 

 from .30^ to .')0° /'.'/ fotiirclio)) punli/ ; reference to tables 

 liascd on the researches of Regiiault, shows that at 32° 

 the quantity of vapour required to saturate the air is suffi- 

 cient to support a column of 0-182 inches of mercury, while 

 at riO° it amounts to U-3C1, or nearly doul^le. Thus the 

 air, instead of being in a condition of giving away its 

 moisture to the walls, has become thirsty, or in a condition 

 to (akf moisliirc mm;/ from them if they are at all damp. 

 This is the case whether the walls remain at .32° or are 

 raised to any higher temper.ature short of that of the air. 



Thus, the action of close stoves and of hot surfaces or 

 pipes of any kind is exactly the opposite of that attributed 

 to them by Dr. Siemens. They dry the air, they dry the 

 walls, they dry the ceiling, they dry the furniture and 

 everything else in the house. 



In our climate, especially in the infamous jerry-built 

 houses of suburban London, this is a great advantage. Dr. 

 Siemens states his American experience, and denounces 

 such heating by convection because the close stoves there 

 made him uncomfortable. This was due to the fact that 

 the winter atmosphere of the United States is very dry, 

 even when at zero. But air, when raised from 0° to 60°, 

 acquires about twelve times its original capacity for water. 

 The air thus simply heated is desiccated, and it desiccates 

 everything in contact with it, especially the human body. 

 The lank and shrivelled aspect of the typical Yankee is, I 

 believe, due to this. He is a desiccated Englishman, and 

 we should all grow like him if our climate were as dry as 

 his.* The great fires that devastate the cities of the United 

 States appear to me to be due to this general desiccation of 

 all building materials, rendering them readily inflammable 

 and difficult of extinction. 



When an undesiccated Englishman, or a German endowed 

 with a wholesome .John Bull rotundity, is exposed to this 

 superdried air, he is subjected to an amount of bodily 

 evaporation that must be perceptible and unpleasant The 

 disagreeable sensations experienced by Dr. Siemens in the 

 stove-heated railway cars, itc, were probably due to this. 



An English house, enveloped in a foggy atmosphere, and 

 encased in damp surroundings, especially requires stove- 

 heating, and the most inveterate worshippers of our na- 

 tional domestic fetish, the open grate, iinariably prefer a 

 stove or hot-pipe-heated room, when they are unconscious 

 of the source of heat, and their prejudice hoodwinked. I 

 have observed this continually, and have often been amused 

 at the inconsistency thus displayed. For example, one 

 evening I had a warm contest with a lady, who repeated 

 the usual jiraises of the cheerful blaze, ikc, itc. On calling 

 afterwards, on a bitter snowy morning, I found her and 



her daughters sitting at work in the billiard-room, and 

 luked tliem why. "Because it was so warm and com- 

 fortable." This room was heated by an H-inch steam-pipe, 

 ruiming around and under the table, to prevent the undue 

 cooling of tin- india-rubber cushions, and thus the room 

 was warmed from the middle, and equally and moderately 

 throughout The large reception-room, with blazing fire, 

 wa-s scorching on C)ne side, and freezing on the other, at 

 that time in the morning. 



The i>ermeability of ill-constructed iron stoves to poi- 

 sonous carbonic oxide, which riddles through red-hot iron, 

 is a real evil, but e.-usily obviated V^y proper lining. The 

 frizzling of particles of organic matter, of which we hear 

 so much, is — if it really does occur — highly advantageous, 

 seeing that it must destroy organic poison-germs. Under 

 some conditions, the warm air of a mom does deposit 

 moisture on its cooler walls. This happens in churche.s, 

 concert-rooms, itc, when they are but occasionally used in 

 winter time, and mainly wanned by animal heat, by con- 

 gregational emanations of breath-vapour, and perspiration 

 — i.e., with warm air supersaturated with vapour. Also, 

 when we have a sudden change from dry, frosty weather, 

 to warm and humid. Then our walls may be streaming 

 with condensed water. Such cases were probably in the 

 mind of Dr. Siemens when he spoke ; but they are quite 

 ditlerent from stove-heating, which increases the vapour 

 cipacity of the heated air, without supplying the demand 

 it creates. 



• In each of my three visits to America I lost abont thirty pounds 

 ill wcJKht, which I rrcovorcil within a few months of my retnm to 

 the " home country" (of English-speaking nations).— En. 



yOLTXG ON THE SUX. 



Bt the Editor. 



IN the beginning of my former notice, I remarked that, 

 although Professor Young is one of those to whom 

 science is very largely indebted for our present knowledge 

 respecting the sun, few would suppose so from the treatise 

 before us. It so chanced that, on the very day when that 

 notice was passing through the press, a review of Prof. 

 Young's book appeared in yalitre, of which the opening 

 paragraph ran as follows : — 



" Since the method of artificial eclipses was introduced 

 in 1868, Prof. Young, the author of the book under notice, 

 has from time to time done good work in utilising the 

 capital climate of his native country, and his relatively 

 superior optical means, to confirm in many essential points, 

 and to add a little shading here and there, to the bold 

 outlines of the new science, for which we are indebted to 

 his predecessors." 



I must confess I read these lines with a sense of regret 

 — almost of shame. It is not fitting that any student of 

 science in this country should be ignorant of the services 

 which our American fellow-workers have rendered in solar 

 research, as in other departments of science. It would 

 be something worse if, knowing what those services have 

 Vieen, they should seek to ignore them. But, apart from 

 this, the reasoning involved in the slur cast on Professor 

 Young's original work is ridiculous on the face of it. One 

 might as reason.ibly say that the Herschels, utilising 

 their larger telescopes, did good work by adding a little 

 shading here and there to the bold outline of telescopic 

 astronomy, for which we are indebted to their pre- 

 decessors ; or that Huggins, Secchi, Lockyer, and others, 

 employing better spectroscopes, have usefully applied the 

 general principles for which we are indebted to Fraun- 

 hofer. Jso one who considers what Young has done can f.iil 

 to see that while even that part of his work which de- 

 pended on the method of artificial eclipses is full of original 



