NOTES. 



TO TABLE VI., p. 289. 



The values of the Magnetic Intensity at Munich and Prague, and at 

 the four Russian stations, were originally expressed in Gaussian units, in 

 which the unit of weight is the gramme, and that of length the metre. One 

 gramme is equal to 15-4426 grains, and one metre to 3-2809 feet. Accord- 

 ingly, to reduce the Gaussian measures of Horizontal Intensity to British 

 units (one grain and one foot), the values of X must be multiplied by 



6 = 2-1695. This has been done in Table VI. 



NOTE TO TABLES V. AND VIII., pp. 286 AND 291. 



The unit of Intensity in Tables V. and VIII. is the ten-thousandth 

 part of the unit of Magnetic Force. 



