544 
went and returned from eaft to weft, has 
procured a longitudinal difference of two 
minutes, thirty-three feconds., =. 
Mr. Dalby calculates, that thefe de- 
grees give a plane of ,4,5 but, as this does 
‘not correfpond with tne meafure of de- 
grees taken in other places, he concludes 
‘that the earth is not a regular cllipfs, 
which is, indeed, the refult of Laplace's 
refearcherst.- tes 
Mr. Herfchell has publithed, in the 
Philofophical Tranfaétions for 1795, @ 
defcription and reprefentation of his 
famous forty -foot telefcope. 
M.-de Roffel, the only furviving officer 
“of the late Capt. Entrecafteaux’s cquip- 
ment, is occupied in London, upon a 
Narrative of this Voyage, which the 
Britifh Admirelty defign to publifh at 
their expence. 
The Vienna Ephemeris, for 1797, be- 
fides a variety of obfervations made at 
Vienna; Buda, Prague,and Cremfmuniter, 
contains calculations of the longitude for a 
great number of towns; and anew deter- 
mination of rhe diftances of the fatellites of 
Jupiter, by Trufnecker. He calculates 
the femi-diameter of Jupiter's equator, at 
1892 feconds; hence the foilowing com- 
parative diftances recult : 
rt fatellite. 5.36 
ad. do. O<3:3) 
3d do. 34.99 
Ath de... 26-34 
Majer Zach, the celebrated aftronomer 
ef Gotha, has publifhed. his Tables of 
Aberration, with anew catalogue of the 
right afcenfions of 400 ‘principal tars, 
which are calculated with as great preci- 
fion as the thirty-four fars of Matke- 
lyne. The inftrument he made ufe of, 
is a meridian telefcope, by Ramicen, which 
is placed with fuch perfect exactnels, that 
he has fcarcely found a perceptible differ. 
ence between eight fars, diftributed in a 
fpace of 162 degrees of the meridian, 
from Antares to Capella, under the pole. 
~ Louis Breguet, a watchmaker of the 
rt eminence in Paris, continues to labour 
on the perfeétion cf chronometers and 
time-Keepers for afcertaining the longi- 
tude. He has invented a {capement, 
upon a principle entirely new, which is 
abfolutely independeat of the movement. 
This ingenious artiit was born at Neuf- 
ch4tel, Jan. 7, 2749, but hasj been 2 
refident in France ever fince the year 
4763. In 1780, he firft began to occupy 
himfelf with bringing the art. to its per- 
fection. : 
-+.Sitizen O’Reily, who has eftaplined a 
) Ealand’s Hiftory of Aftronomy. i 
Sur. 
large glafs manufaétory at Gros-Callou, 
manufactures flint-giafs for acromatic te- 
lefcopes. Citizen Carouch has made a 
experiment, and pronounces them of an 
very excellent quality. * 
Don Denis Alcala Galeano, captain of 
a Spanifh veffel, has prefented to the 
Board of Longitude two memoirs on the 
Calculation of the Longitude and Latitude. 
We are indebted. for chefe refearches to 
the voyage of Don Alexandre Malafpina 
to the South Seas, in 1789, which -voyage 
has procured us feveral interefting obfer~ 
vations on the flowing and ebbing of the . 
tides on both coafts of America, 
Letters from Spain, dated Nov. 6th, 
inform us, that the Prince of Peace has 
eftablifhed profefors of Aftronomy, the- 
oretical, practical and phyfical, and like- 
wife for the application of geography to 
the purpofes of navigation. He has 
founded likewife a new military corps, 
under the title of Cofmographical Engineers 
of State; the members of which were 
prefented to the king and queen. on the 
30th of Odtober. 
The Prince of Peace has requefted Mr. 
Herfchell to furaith him «with a telefcope 
of twenty-five feet, and M. de Mendoza, 
a Spanith officer, has been commiffioned 
to urge its execution. — 
. Jofeph Chaix, a native of Saint Phil- 
ippe, about cight leagues difiant from 
Valenin, after having fucceflively ftudied, 
for feveral years, the {ciences of aftronomy 
and geography, both in France and Eng- 
‘land, has been appointed to fuperintend 
the prand obfervatery building at Madrid. 
In Germany, M. Schroter has printed 
_a work, under the title of 4pbroditegra, bie 
cal Fragments, containing the refult of his 
obfervations on the figures, the fpors, 
mountains, and rotatien of Venus, on 
which fubje&t .he has already publithed 
feveral communications in the Loadon 
Philofophical Tranfaétions, the Memoirs 
of Goettingen, Erfurt, and Berlin, and in 
the Berlin Ephemeris. He has difcovered 
that the mountains in Venus bear nearly 
the fame proportion to the diameter of 
this planet, as the mountains in the 
moon to its diameter; and that, as in the 
moon, the moft and higheft mountains im 
Venus are towards the fouth. 
The cotation of Venus appeared to him 
to be twenty-three hours twenty-one mi- 
nutes. The alterations, which he ob- 
ferved in the fpace of two hours, in the 
horn of this planet, appeared to him te 
indicate, that the equator of Venus forms 
a large angle with its ecliptic, and that of 
cena 
al hs 
