Chase.] 3gg [February. 



ON SOME GENERAL CONNOTATIONS OE 

 MAGNETISM. 



BY PLINY EARLE CHASE. 



Messrs. Baxendell (Proc. Manchester Lit. and Phil. Soc, 

 1865-6) and Bloxam (Proc. Meteorolog. Soc, Nos. 28, 32), 

 have pointed out certain interesting resemblances between the 

 curves of magnetic declination and those of rainfall, or of the 

 " changes that occur in the aqueous element — that is to say, 

 changes from and to the solid, fluid and vaporous states." But 

 Mr. Glaisher (Proc. Meteorolog. Soc, No. 33, p. 23) infers 

 from a careful discussion of six years' observations at the Royal 

 Observatory, Greenwich, that " there does not seem to be any 

 connection between the diurnal movements of the declination 

 magnet and the diurnal fall of rain. The curve of diurnal rain- 

 fall, from all the years, seems in some way connected with the 

 position of the sun ; the least frequency of rain, and the small- 

 est falls, take place during the morning hours, whilst the sun 

 is ascending ; the greatest frequency and most rain take place 

 in the afternoon hours, whilst the sun is descending." 



An examination of the curves or of the tables from which 

 they are constructed, at Girard College, St. Helena, Cape of 

 Good Hope, Hobarton, Toronto, Nertschinsk, Pekin, Kew, 

 Greenwich, Makerstoun, and elsewhere, shows that there is an 

 intimate relation between the variations of the several meteoro- 

 logical elements, temperature, elasticity of vapor, gaseous pres- 

 sure, pressure of the wind, barometric pressure, electricity, 

 magnetic declination and inclination, vertical and horizontal 

 force, and that all these phenomena depend either directly or 

 indirectly upon solar action. Whether that action is simple or 

 multiform in its origin, whether the consequent changes ma- 

 terially modify each other by their mutual interaction, and 

 whether the magnetic forces are specific or derivative, celestial 

 or terrene, cosmical or local, are questions which are still sub 

 judice. Major-General Sabine (Phil. Trans., vol. 153, p. 301), 

 after noticing " the concurrent evidence of the three observa- 

 tories of Toronto, Hobarton, and Kew, for the existence of . . . 

 an increase of the dip and of the total force, and a deflection 

 of the north end of the declination magnet towards the west, 

 in both hemispheres, in the months from October to March, as 

 compared with those from April to September," says, " it seems 



