128 Observations relating to the Operations undertaken 
observations of the latitude. I was now certain of success, and 
perseverance was only necessary. It was no small disadvantage 
that Captain Mudge became greatly indisposed;.and a whaler, 
haying touched at the island, I with difficulty prevailed upon him 
to return to a more genial climate. He invested me with all 
the powers of his father, and afforded all necessary assistance. 
When left alone, I found the advantage of residing with Mr, Ed- 
monston. His kindness increased with my difficulties, The 
operation of the repeating circle required two persons, one to 
follow the star and another to mark the indications of the level. 
A young carpenter, who by his fitting up the observatory had 
given proof of his intelligence, (and who, similar to the generality 
of the peasants in Scotland, could read, write, and cipher,) was 
by the advice of Mr. Edmonston employed for the latter part of 
the observation. He acquitted himself better than a more learned 
assistant; for he observed and marked my level with the fidelity 
and the accuracy of a mechanic, and even. to satisfy my impa- 
tience would not admit my results until the bubble of the level 
was in a state of perfect immobility. With this assistant, in two 
months I collected 38 series of the pendulum, each of five or 
six hours, 1400 observations of the latitude in 55 series made 
equally on the south and the north of the zenith, and, to regu- 
Tate my clock, about 1200 observations of the absolute heights 
of the sun and stars. After this I was chiefly employed in ob- 
serving, and only made three or four calculations; but the re- 
mainder sihce my return home I have found accurate. The re- 
sults which are deduced from them, being combined with those 
of Formentera of the are of France, give for the flattening of 
the earth exactly the same value which is deduced from the 
theory of the moon, and the measurement of the degrees com- 
pared at great distances. This perfect agreement between de- 
terminations so different, shows at once the certainty of the re- 
sult, and the sure method which science employs to obtain it. 
Nor was this point of precision reached without great difficulty, 
as is obvious from the fact—that the variation of the length of 
the pendulum by which the flattening is measured, is in all, from 
the equator to the-pole, but four ‘ millimetres,” less than two 
lines, and from Formentera to Unst, one “ millimetre and a 
half,” or less than three-fourths of a line. This small portion; 
however, exhibits and measures even with great accuracy the 
flattening of the whole terrestrial spheroid, and proves that in 
spite of slight accidents of composition.and arrangement, which 
this exterior and slender surface presents, the interior of the masg 
is composed of strata perfectly regular, and subjected to the.laws 
of superposition, density and form, which a. primitive state of 
fluidity had assigned to them. Longe ) 
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