Natural Philosophy. — Magnetism, S8T 
soff, one of the most northern of those districts, it rmned abun- 
dantly on the 8th December, a circumstance which had never 
occurred in the memory of the oldest inhabitants. 
Near Buenos Ayres there fell in the month of December 18S1 
such a quantity of snow, that the communication between that 
city and Lima was entirely interrupted. The cold which pre- 
vailed in the different parts of South America is a most extra- 
ordinary phenomenon, and the inhabitants of Peru and Chili 
have considered it as a true calamity. — Bihl. Unwerselle^ June 
1822, p. 108. 
MAGNETISM. 
11. Pip of the Needle at London in 1821. — From a series of 
numerous and accurate experiments made by Captain Edward 
Sabine, he obtained the following measures of the dip of the mag- 
netic needle at London, in the Regent’s Park. 
By ten experiments with Tobias Mayers’ * needle, - 70®. 
By the limes of oscillation in the magnetic meridian, and 1 
in the plain perpendicular to it. Mean by three r ^ 
needles, 
By the times of vertical and horizontal oscillation, . 70. 2.6 
Mean, 70. 3.2 
Hence Captain Sabine concludes, that 70° 3' is the mean dip ^ 
of the needle at London, in August and September 1821, with- 
in four hours of noon. 
As the observations of Nairne and Cavendish give 72° 25' for 
the dip in 1774, we obtain S'. 02 as the mean annual rate of dimi- 
nution between 1774 and 1821. 
Taking Mr Whiston’s determination of the dip in 1720, viz, 
75° 10', which Mr Cavendish considered as accurate, the annual 
diminution is S'.05. 
II. CHEMISTRY. 
12. Nitrogen Springs in Rensselaer CouTdy, Neiv-Yorh.^ 
The most remarkable springs in the county of Rensselaer, 
are the nitrogen springs in the south-east corner of the towrf of 
Hosick. They are about six miles south-west of the village of 
Bennington, in Vermont. There are three springs comprised 
* Mem, JR. S, Gotting, 1814. 
