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On-the Trigonometrical Survey. 4} 
in the Mediterranean, and other stations on the French meridian, 
proceeding from thence to Dunkirk. 
The object of these experiments is, to ascertain the force of 
gravity at certain parts of our meridian, as connected with that 
of France and Spain. The pendulum is now erecting in Leith 
Fort, where every convenience offers itself for the experiment, 
and every wish has been anticipated by the chief engineer, Sir 
Howard Elphinstone. When the operations shall be completed, 
we propose to proceed to Kirkwall in the Orkneys, and near 
that place, or some more convenient situation, if any such can 
be found, we shall again set up the pendulum, and the ordnance 
zenith sector, the workmanship of the late celebrated Mr. Rams- 
den. Thus, while the experiments are carrying on to ascertain 
the force of gravity in that quarter, the observations will be made 
ou proper stars near to the zenith, hereafter to be also observed, 
in finding the amplitude of the whole meridional are. The base, 
now nearly completed in its measurement by Captain Thomas 
Colby of the Royal Engineers, in the vicinity of Aberdeen, will 
verify the sides of the triangles towards the northern part of our: 
are, connecting the Orkney Islands with the main land. It is 
probable that M. Biot and myself will leave this quarter for In- 
verness (where the ordnance sector is now deposited) about the 
end of this month ; and we think it likely, if the weather should 
be fair, that our operations in the Orkneys will be finished early 
in August. When these observations shall be completed, we 
shall proceed to Yarmouth, on the coast of Norfolk, whic!s lies 
nearly on the meridian of Formentera produced, and there we 
hope to be joined by M. Arago, member of the Institute of 
France, and one of the Commissioners of the Board of Longitude. 
By this co-operation, having accurately ascertained the latitude 
of this place, a notable addition will be made to the arc running 
south from Formentera to Dunkirk, independent of the great 
one, running north to the Orkneys; for we hope that the dif- 
ference of longitude (being only a few degrees) will not have suf- 
ficient influence to interfere with the importance of this last con- 
nexion. We will repeat the experiments of the pelldulom at 
Yarmouth, and afterwards proceed to Blackdown, near Wey- 
mouth, to the meridional limit of the English are, where, having 
again observed the pendulum, and made observations with the 
zenith sector, on the same stars as are to be observed in the 
Orkneys, our united operations will close with Messrs. Biot and 
Arago erecting their clock at the Royal Observatory at Green- 
wich, Jt was to be always expected, that whenever peace should 
arrive, the science of France and England would affiliate, and by 
the united operations, in this par ticular, determine the magni- 
tude and figure of the earth, by experiments carried on on a greater 
scale 
