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heat, according to Captain Duperrey’s supposition, but as a 
source or centre of magnetic attraction, if I may dare say so 
in the present uncertain state of science. 
‘The mean results of the observations made by us on 
magnetic intensity of forces, confirm very nearly the ratio 
between the equator and our latitudes, as first given by our 
distinguished countryman Captain Sabine. The dip was 
13°. 9’. but varied a little under the sun’s influence. 
“The maxima and minima of the barometer’s range, 
confirmed partly M. Boussingalt’s results. 
‘The mean temperature of the place, as given, Ist, by 
the daily observation of the thermometer; 2nd, the heat of 
springs; and 3rd, that of the ground at small depths, was 
27.5 grades; nevertheless, the bottom of an Artesian well, 
200 feet deep, was 24.0 grades, being much colder than at 
the surface. This was measured three times, as it seemed 
contrary to our received theories on a geocentric focus of 
heat. 
““M. Selligue of Paris, has succeeded in making a 
folding iron barometer, which has been observed every day 
after a thorough shaking. It has not altered its primitive 
error of .001 metre. I confess that I am rather sanguine 
about this instrument, which I shall carry with me to Egypt 
and beyond the Red Sea.” 
M. Abbadie is at present in Abyssinia, whence he will 
proceed along the shores of the Red Sea, 
Professor Lloyd communicated to the Academy the 
results of his observations on the diurnal march of the 
horizontal needle, made on the 31st of August and 13th of 
November, 1837. 
These observations having been made with the apparatus 
of Professor Gauss, Mr. Lloyd commenced by describing 
the construction and uses of that apparatus, the principal 
parts of which he exhibited to the Academy, He then ex- 
