Xov. 10, 1S82.] 



o KNO\A^]LEDGE • 



391 



illustrate the method adopted for attaching the motor 

 to the table or base of the machine to be worked. 

 Fig. 3 illustrates the battery of si.K large single-fluid 

 bichromate cells. Xormally the zinc and carbon plates 

 are kept out of the solution by means of a spring. 

 When it is required to work, the machinist gently 

 presses the treadle (drawn on the right of the figure), 

 causing the plates to bo immersed. By this arrangement 

 there is a minimum consumption of the constituents of the 

 cells, while the movements of the plates help to keep the 

 solution in a state of agitation, and so prevent rapid polari- 

 sation. With the aid of Fig. 2 the reader may trace the 

 course of the current from the positive polo of the battery 

 through B B to the commutator, thence through the 

 armature back to the commutator, and so on to the nega- 

 tive pole of the battery. The total weight of the motor is 

 2.1 lb., and the full speed of the armature 5,000 revolu- 

 tions per minute, but it will be obvious on reflection that 



this speed may easily be moderated by varying the depth 

 to which the plates are immersed. It is also worthy of 

 notice that it is impossible for the sewing or other 

 machines to be impelled in the wrong direction. With a 

 greater current more work can naturally be accomplished, 

 and we may mention that motive power equal to 1-h.p. 

 is said to have been obtained. The current may bo 

 derived from a dynamo, when a number of the motors 

 may be placed in the circuit It promises, therefore, to be 

 very useful in many small industries, more especially 

 where the work to be done is small, and distributed over 

 the various parts of a house or worksliop, and under such 

 circumstances, in fact, as would render the use of steam 

 inadmissible. 



This useful little motor, the invention of Mr. W. Gris- 

 com, of Philadelphia, is consequently almost universally 

 admirtxl for its size and simplicity, its cheapness and its 



efficiency, and we hope the- efforts of the company in 

 whose hands it is entrusted will be becomingly appre- 

 ciated. 



THE SUN'S FUEL. 



WHILE thanking Mr. Proctor for his friendly notice 

 of my " Science in Short Chapters " (Knowledge, 

 p. 377), I must ask leave to correct his total misappre- 

 hension of my theory when he describes me as supposing 

 that the sim, after having obtained his gravitation equiva- 

 lent of the universal atmospheric matter, generates more 

 heat l)y merely compressing on one side and rarefying on 

 the other the same unaltered kind of matter. This would 

 be quite on a level with the customary parado.x of the per- 

 petual motioners, and closely resembUng what one would 

 get by a pair of reciprocating pistons compressing the air 

 of one cylinder by the elastic expansion of the other. 



Mr. Proctor correctly represents my view of the effects 

 of the original aggregation and condensation of atmo- 

 spheric matter about the sun ; but as regards my attempt 

 to solve the great problem of the maintenance of solar 

 energy, he has not even crossed the threshold of the 

 argument, and has evidently " taken as read " my exposition 

 of its essential points ; for I cannot believe either that I am 

 incapable of explaining, or he of understanding, what I 

 intended to expound. 



The threshold of the argument to which I allude, and at 

 which ]Mr. Proctor halts, is that the heat evolved by this- 

 original aggregation and compression would dissociate the 

 atmospheric compounds (notably water vapour), and thereby 

 store a reservoir of heat ; but beyond this, I have shown 

 that the recombination and explosion of the whole of this 

 is restrained by the limitation of radiation due to the 

 "jacket" or envelope of the chromatosphere and outer 

 atmosphere of the sun ; this limitation determining the 

 depth of the photosphere, or amount of surface combustion 

 or recombination. Mr. Proctor has not penetrated even 

 this, the vestibule of the argument. 



A step further brings us to that " swaying of the sun 

 around the centre of gravity of the solar system which 

 Mr. Williams regards as an all-important point of his 

 theory," and of which point Mr. Proctor altogether fails 

 to grasp the significance. I maintain that this produces 

 the irregular angular or rotatory velocities of the different 

 portions of the solar photosphere which Carrington demon- 

 strated (the equatorial portions making a complete revolu- 

 tion in 30^6 days, while those in latitude of about 30^ 

 revolve in 28 36 days), and that such irregularity, pre- 

 sumably shared by the outer vapour jacket, must produce 

 vortices or cyclones on and about both borders of tlie 

 equatorial solar zone ; that these vortices must rip open 

 that jacket thereabouts, and thus remove the restraint to 

 combustion in such spot-s. The consequence of this (as 

 demonstrated by the laboratory researches of Deville, 

 Bunsen, and others) must be explosive outbursts in the 

 trail of these vortices of a magnitude corresponding to 

 themselves. This ripping open of the solar integuments, 

 and consequent ejection of his dissociated entrails, is what 

 we observe in the spots and prominences. 



But what must follow the formation of this partial and 

 local \acuum produced by sucli ejection ! Evidently an 

 inrush to restore the broken equilibrium of general gaseous 

 pressure. I need scarcely work out the progressive steps 

 of this restoration, first from the contiguous gaseous 

 matter, tlien from the further distant, and linally from a 

 jiorlitiii of that cylinder of interstellar atmospheric matter 

 wliich by the solar translation in space is (as I maintain), 



