AtmoEwhere 



A tt HIM 



SCIENTIFIC SIDE-LIGHTS 



54 



we discuss the possibility of life in other 

 worlds we shall do well to remember that 

 Saturn may be possibly a warm world, and 

 Mercury conceivably a cold one. LANGLEY 

 New Astronomy, ch. 5, p. 136. (H. M. & 

 Co., 1896.) 



269. ATMOSPHERE A VAST HYDRO- 

 ELECTRIC MATOttNE Friction a General 

 Source of Electricity Air and Earth 

 Mutually Electrified. It has been found 

 that friction is a far more general source 

 of electricity than was at first believed. In 

 fact, electrical phenomena appear to be a 

 constant result of friction, whatever may be 

 the nature of the substances rubbed. Thus 

 it is developed by blowing air over glass. 

 . . . When, now, we consider that the 

 air is always rubbing over the surface of 

 the earth, at times with great rapidity, we 

 shall not be surprised to learn that both 

 bodies are constantly in an electrified condi- 

 tion, the earth being generally charged 

 negatively and the atmosphere positively. 

 Even in fair weather it is always possible 

 to detect the presence of free electricity in 

 the atmosphere; and during a storm, when 

 clouds filled with drops of water are hur- 

 ried over the surface, grinding against the 

 hills and the trees, or against each other, 

 the atmosphere becomes a vast hydro-elec- 

 tric machine, whose sparks are the light- 

 ning and the noise of whose discharges the 

 thunder. COOKE Religion and Chemistry, 

 ch. 2, p. 59. (S., 1891.) 



27O. ATMOSPHERE, MAGNETIC 



Aura around Electrical Conductor. The 

 electrical current is competent to produce 

 effects not merely in its channel or con- 

 ductor like water turning a wheel but to 

 influence bodies entirely outside of that 

 channel. It causes, around its conductor, a 

 peculiar aura or atmosphere like that 

 around the poles of a magnet, but differing 

 from the latter as a whirlwind differs from 

 a steady gale. It converts the conductor 

 into a magnet, which, like other magnets, 

 is capable of influencing magnetic bodies to 

 become magnets. It also converts magnetic 

 bodies, around which the conductor is 

 wound, into magnets; and a bar of iron in 

 this way is given all the properties which 

 it would have were it normally and nat- 

 urally a magnet, or piece of lodestone. 

 PARK BENJAMIN Age of Electricity, ch. 6, 

 p. 87. (S., 1897.) 



271. Aura or Field of 



Force around the Poles of a Magnet. It 

 appears, therefore, that around the pole of 

 a magnet exists this strange atmosphere 

 a so-called " field of force," in which exist 

 strains and pulls and pushes as if a host 

 of infinitesimal beings were at work seiz- 

 ing upon the filings, and arranging them to 

 make them accommodate themselves to this 

 new condition of affairs. And the result of 

 it all is, that we recognize seeming lines of 

 force radiating from the pole. It is a won- 



derful atmosphere, that magnetic field. We 

 have only to move a piece of iron in it, in 

 a peculiar way, to make speech heard miles 

 distant, or to produce the light which is 

 weaker only than the sun in power; and 

 what still stranger things may yet be done 

 no one knows. PARK BENJAMIN Age of 

 Electricity, ch. 6, p. 75. (S., 1897.) 



272. ATMOSPHERE OF DEATH A 



Barbarous Experiment Suffocation of a 

 Dog Gas Bailed Out Extinguishes Candle. 

 Many natural springs of carbonic acid 

 have been discovered, one of which I should 

 like to introduce to your notice. In the 

 neighborhood of the city of Naples there is 

 a cave called the Grotto del Cane, a name 

 given to it for a curious and culpable rea- 

 son. During one of the eruptions of Vesu- 

 vius I paid a visit, in company with two 

 friends, to Naples, and went to see, among 

 the other sights of that wonderful region, 

 the Grotto of the Dog. At a place adjacent 

 we met a guide and some other visitors. 

 At the heels of the guide was a timid little 

 quadruped, which, for the time being, was 

 the victim that gave the cave its name. 

 We could walk into the cave without in- 

 convenience, knowing, at the same time, 

 from the descriptions we had heard and 

 read, that our feet were plunged in a stream 

 of heavy carbonic acid flowing along the 

 bottom of the cave. The poor little dog, 

 much against its will, was brought into the 

 grotto. The stream of carbonic acid was 

 not deep enough to cover the animal; its 

 master, accordingly, pressed its head under 

 the suffocating gas. It struggled for a 

 time, but soon became motionless appar- 

 ently lifeless. Taken into the air outside, 

 through a series of convulsions painful to 

 look upon, it returned to life. 



The experiment is a barbarous one, and 

 ought not to be tolerated. There are many 

 ways of satisfying the curious without 

 cruelty to the dog. I made the following 

 experiment, which seemed to surprise the 

 bystanders. Placing a burning candle near 

 the bottom of my hat, in the open air out- 

 side the cave, I borrowed a cap, and by 

 means of it ladled up the heavy gas. Pour- 

 ing it from the cap into the hat, the light 

 was quenched as effectually as if water had 

 been poured upon it. Made with glass jars 

 instead of hats, this is a familiar labora- 

 tory experiment. TYNDALL New Frag- 

 ments, p. 338. (A., 1897.) 



273. ATMOSPHERE OF THE SUN 

 Far Exceeds the Central Mass Mam 

 Body of the Luminary Commonly Unseen. 

 W T hat we see of the sun under ordinary cir- 

 cumstances is but a fraction of his total 

 bulk. While by far the greater portion of 

 the solar mass is included within the photo- 

 sphere the blazing cloud-layer, which 

 seems to form the sun's true, surface, and is 

 the principal source of his light and heat 

 yet the larger portion of his volume lies 

 without, and constitutes an atmosphere 



