68 Connexion between the Theory of the Earth and the 
investment of but a comparatively small capital would soon give it 
another complexion. We have as much water power here as _ 
they can possibly have in Oberstein or Bohemia, which are the 
grand marts of Europe. 
Remarks.—We are happy to become acquainted with the ex- 
perience of a sensible practical man like Mr. Taber, and to learn | 
from him the state of this comparatively infant branch of manu- 
facture among us, and especially in New York. a 
We should be gratified to receive similar communications Pie | 
our other large cities, and especially from Philadelphia, where we | 
suppose that all the arts relating to gems are farther advanced than ~__ 
any where else in this country. Mr. Taber does not mention the | 
incomparably fine tourmalines of Paris, Maine—some of which 
as polished in London, and now in the hands of Prof. Charles U. 4) 
Shepard, of this place, almost rival the ruby and the emerald in | 
color and beauty, and far exceed them in size. They are we 
believe without a parallel in the world.* The fine spinelles and 
other remarkable minerals of Orange Co., New York, and of the 
neighboring parts of New Jersey, as well as the splendid transpa- 
rent and perfect beryls of Haddam, recently brought to light by 
Prof. Johnston, of the Wesleyan University at Middletown, Con- 
necticut, some of them being little inferior in beauty to the eme- 
rald, asl far surpassing it in size, we suppose are unknown toour 
elec, —Eds. 
Art. XI.—On the Connexion between the Theory of the Earth 
and the Secular Variations of the Magnetic Needle; by Joun — 
H. Larturop, Professor of Mathematics and Natural Philosophy, | 
Hamilton College, Clinton, N. Y. 
(Communicated for this Journal.) 
In the course of some geological speculations I recently had 
occasion to make, with a view to the application of the prevail- 
ing théory of the earth to the solution of some physical problems, 
I was led to consider its bearing on the phenomena of terrestrial 
ee 
= 
> ‘The information secnived by the recent return of Prof. Shepard from London, — 
places this beyonda doubt. Nov. 13, 1839. 
Se 2 
