2 



INCLINATION AND DECLINATION 



curious practical result of these latter investigations leading to the 

 correction of that disturbance, under which the magnetic needle on board 

 ship had till then laboured, from the influence of the iron-work about the 

 vessel — offers an example of that utility which, though it may not always 

 be obvious, yet is assuredly sooner or later the fruit of an assiduous cul- 

 tivation of science. 



Nor have the more ordinary phenomena of magnetism been neglect- 

 ed in this general movement. An immense mass of results have been 

 collected by our voyagers to the north pole, relating to the declination 

 and inclination of the magnetic needle, as well as the intensity or direc- 

 tive power. Other observers have assisted, and as far as Europe and the 

 northern regions are concerned, little, perhaps, remains to be desired in this 

 branch of experimental Physics. But with regard to the other countries 

 of the globe, the facts that have been collected are " few and far between." 

 I am happy, therefore, to be able to communicate the following observa- 

 tions made in this country by two members of this Society. We have 

 not yet had any observations of the kind recorded in India, and I doubt 

 not the Society will receive favorably this attempt to fill up the blank 

 that exists. Let us hope, too, that the publication of these results may 

 stimulate other enquirers ; and that, by their exertions, we shall yet have 

 correct determinations of the three elements of magnetic inclmation, 

 declination, and intensity, at all the principal places of our Indian empire. 



The results now offered comprehend the determination of the declina- 

 tion and inclination of the magnetic needle. The first series made on board 

 the French Corvette La Chevrette, is by M. de Blossville. I have not 

 thought it necessary to translate his introductory notice, as preferring to 

 retain his own expressions. 



" Les observations que j'ai faites dans les differens lieux on La 



