4 
208 | Progress of the Scvences. HELE A 
° - . M . - 6 } . . Pied ; 
“magnetic force; that this force diminish- course of time had occasioned in our 
ed progressively, in proportion to the dis- totse and the Paris pint. 
tance from the terrestrial equator. MM,—. At the same time, M. Cavendish, by 
Biot and Gay Lussac remarked, mm their means which are only Coulomb’s balance 
aréostatic ascensiOns, that the distance of Torsion, constructed on a larger scale, 
from the earth caused no perceptible determined the density of the earth, 
diminution in the intensity of magnet-_ which he found to be five and a half 
ism, although M. Gay Lussac, in the times greater than that of water. 
last of these ascensions, rose to the Roy and Ramsden observed the dila- 
greatest height to which any one ever _ tations of glass, and of several metals, in 
reached, as it exceeds that of all the order to be prepared for the measurement 
xrountains of the globe. _ of two bases in the trigonometric opera- 
Dr. Wollaston had contrived an ex- tion for England. Lavoisier and’ Borda 
tremely siniple apparatus, by means of determined the dilatations of latten and 
which he measured, with accuracy, the platina, Borda and M. Cassini measured, 
refraction and reflection of transparent -by observations of a precision quite no- 
substances. M. Malus, by avery inge- vel; the length of the pendulum which 
nious addition, extended the use of itto beats seconds at Paris, in order to obtain 
opaque substances; and his analysis has exactly the ratio of this pendulum with 
enabled him to: discover an error which the metre. About the same time, a new 
had escaped Dr. Wollaston, who had branch of physics sprung from an expe- 
not the means of submitting to experi- riment of Galvani, which all natural phi- 
tment that part of his theory. losophers hastened to repeat and divers 
M. Ramond,~on the Pyrenees, had sify. M. Humboldt had the courage to 
discovered a very slight correction to be undergo it himself, by submitting to the 
prade in the co-efficient of the canon of most acute pains; in order the better to 
BM. Laplace, for measuring the height of ascertain,effects, frem which very impors 
a mountain, on which a barometiic ob- ° tant knowledge was expected, respecting 
servation is made. M. Biot, in yepeat- animal economy, and, perhaps, the prin- 
ing the physical experiments on which ciple of life itself. Hf these brilliant ex-. 
IM. Laplace had ffunded histheory,disco-, pectations have not yet been realised, 
vered that the correction was necessary; Galyanisin has, at least, given birth to 
and these experiments of M. Biot gave the Voltaic pile, which soon disclosed 
him the co-efficient of M. Ramund, as to us real wonders, which, at this, mo« 
they gave the refraction of M, Delam- ment, excite the most lively interest.— 
bre. This same labour led to other ia- M_ Gist has given a very elegant theory 
teresting consequences, onthe refracting of this apparatus, but which supposes 
power of the different gases, and to a two principles ; one of them, though a 
method of estimating, with more pre- ery near approximation, and the must 
cision than even by chemical processes, simple that can be imagined, has not, 
the composition of various substances; however, been placed, by. experiment, 
such, for instance, as the diamoud, which . totally beyond the reach of doubt. 
he thnks to be partly composed of 
oxygen. 
While the French astronomers were 
\ 
GEOGRAPHY, VOYAGES, AND TRAVELS, 
At the epoch of 1789, all nations 
' ( seemed to vie with each other, in im- 
measuring the dimensions of the earth, proving the descriptions of their states 
to establish the foundation of the metri- and of the seas which surround: their 
eal system, Sir G. Shuckburgh endea- coasts: The taste, excited by the for 
voured to determine the ratio of the tynate and brilliant voyages of Bougain- 
measures used in England, by the pen- yiile and Cook, was not diminished by 
dulum which beats seconds at the lati- the disastrous, though’ not altogether 
tude of 51 degrees anda half. His ex-  yseless, expeditions of La Peyrouse, and 
periments were very accurate; but, on Entrecssteaux, The Enelish have avail- 
comparing the length of his pendulum eq themselves of the advantages of their 
with two-standard rujes, constructed by situation. While their African Society di-) 
two eminent artists, he was surprised to rected its attention to countries totally un= 
discover, that the two rules were not ex~ known; while their Hornemann met with 
actly of the Same length, which shews the most distinguished reception from the 
the inconvenience of such arbitrary mea- Conqueror of Egypt; while Munyo Park 
sures, the models -of which exist nO braved the greatest dangers to open new 
where in nature; of this we had’ before channels to the commerce of bis country y 
& proor wm the alterations, which the while Plinders encountered dangers still 
; : more 
