Terrestrial Magnetic Intensity. 169 



Proceeding similarly with the mean (and very regular) 

 ratios of change in Art. 18, we shall find 



fl833, May 7, 2*52114 



I 1835, May 4, 2-53100 



Log. T P < ... July 20, 2-53203 



| ... July 30, 2-53216 



L .- Aug. 10, 2-53230 



23. The various corrections now considered being fixed, 

 the application of them, and the deduction of the horizontal 

 intensities related to Paris as unity, becomes easy. I have 

 employed printed forms for this purpose, arranged in pages 

 each containing 5 reductions after the following model, and 

 bound up in books. 



Third Series. Vol. 1 1. No. 66. Aug, 1837. 



