November 1, 1895.] 



SCIENCE. 



589 



torial insolation,' and has treated the whole 

 question of insolation, it seems to me to have 

 considered, in the last factor, the most impor- 

 tant source of energy for disturbances of the 

 atmosphere. We receive from the sun daily 

 sufficient radiant energy to melt a sheet of ice 

 six inches thick (180 ft. annually, Langley). 

 Tvifo-thirds of this is caught by the atmosphere, 

 either on its way in or out. A rough calcula- 

 tion shows this energy sufficient to raise the 

 temperature of the entire atmosphere a little 

 over 3° C. daily. When we remember that 

 this action is concentrated upon a portion of the 

 atmosphere, which is changing daily and an- 

 nually, and upon certain strata, depending 

 upon their relative humidity, it seems almost 

 superfluous to seek for other forms of energy to 

 account for the activities of the air. 



The keystone of the new theory seems to be 

 the assumption that the sun is a magnet and its 

 activity as such aifects us to a marked extent. 

 The ratio of the sun's diameter to its distance 

 from the earth is about 1 to 100. It is almost 

 inconceivable that the best steel ball magnet 

 one foot in diameter would affect the most deli- 

 cate instrument at a distance of 100 feet. Pos- 

 sibly an electromagnet might, but how shall we 

 conceive the sun as an electromagnet, even 

 with the assumption of a solid nucleus and dis- 

 tant envelope. No trace of perrnanent magne- 

 tism has ever been observed in a body that is 

 within several thousand degrees of the sun's 

 temperature ; magnetic effects vanish at 800° 

 to 1000° C, except those due to electric cur- 

 rents. Suppose the sun to be a magnet, any 

 distribution of magnetism at all adapted to the 

 new theory would give a field at our distance 

 homogeneous in its distribution in solar longi- 

 tude, and hence the axial rotation of the sun 

 would not affect the earth's magnetic state ; 

 this would be done only by variations from time 

 to time in the intensity or distribution of the 

 sun's magnetism. In no case can the earth's 

 total magnetization be due to the sun's field. 

 It is far too weak to induce such intensity even 

 in the most susceptible metal, much less in 

 •such non-magnetic material as the earth's crust. 

 Furthermore, if such were the case the mag- 

 netic poles would pass round the earth daily, 

 somewhere between latitudes 60° and 75°. 



It would appear that Professor Bigelow at- 

 tributes to magnetic lines of force entirely novel 

 properties. Propei-ly speaking, lines of force 

 are directions only, and if electricians refer to 

 them as containing energy they really mean 

 tubes of force. 



There can be no radiation along a line or tube 

 of force. When the author speaks of the sun as 

 a 'magnet in dynamic operation,' and 'live 

 lines of magnetic force originating in the sun 

 and propagated to the earth in wide sweeping 

 curves,' he uses terms to which students of me- 

 chanics and physics have fixed definite mean- 

 ings, but in a way qviite unintelligible to them. 

 Also when variations of terrestrial latitude ai'e 

 attributed ' to the action of stresses in the ether 

 at the surface of the earth, due to the mechan- 

 ical forces generated in the ether by the trans- 

 mission of radiant energj'. ' If we are to admit 

 a new form of radiant energy we must have good 

 cause indeed. No doubt we receive from the 

 sun radiant energy of wave-lengths varying 

 from fractions of a micron to possibly many 

 kilometers, and this varies in nature from ac- 

 tinic to electric, from light to Herz waves of gi- 

 gantic size. 



Again, with reference to the reversal of the 

 cui'ves, Professor Bigelow' s magnetic theory 

 seems incapable of explaining such a phenome- 

 non. To doubt that a line of magnetic force is 

 continuous from one pole to the other, in fact, 

 is a closed curve, is to doubt the most funda- 

 mental principle of magnetism as at present ex- 

 perimentally established. Electrostatic tubes, 

 or lines of force may be open curves, but the 

 difference between the two cases must be evi- 

 dent. It is difficult to see the connection be- 

 tween these hypothetical magnetic phenomena 

 and the temperature of our atmosphere. It is 

 too permeable and too bad a conductor to 

 catch much of the slow radiant energy, either 

 magnetic or electric. 



In view of these difficulties among otliers are 

 we not warranted in asking a fuller justification 

 of a hypothesis, seemingly based upon curves of 

 small residuals, obtained by a delicate and ap- 

 parently complicated system of selecting and 

 plotting. 



Wm. Halt.ock. 



Columbia College, October 24, 1895. 



