'The Transactions of the Bombay Geographical Society. From December 1854 to March 1856. (New Issue.) Edited by the Secretary. Volume XII.' [‎92] (109/258)

XCil
PROCEEDINGS OF THE SOCIETY.
commenced in 1800 under the auspices of Colonel Lambton, ofH. M.’s
33rd, who came out under the Duke in 1786, and was spared to preside over
it for above twenty years. He was succeeded by Colonef Everest, who again
was succeeded by Colonel Waugh, the present Surveyor General, so that in a
work of extraordinary labour, and where those engaged in it must be exposed
in an unusual degree to the injuries of the climate, three Officers, of rare
industry and ability, have been spared for the long period of half a century to
preside over a department in which change is singularly undesirable. The
history of the instruments with which the survey was commenced is a curious
one. The steel chain, the only measuring instrument available, had been
made by Ramsden, on the pattern of that used by General Roy. It was sent
out with Lord Macartney’s expedition as a present to the Emperor of China,
a more preposterous one could by no chance have been chosen. His celestial
Majesty declined the gifts intended for him, and they appear to have been
brought to Calcutta by Lord Mornington, and thence sent down to Madras,
the only place in India where there is an Observatory. So soon as Seringa-
patam was taken and Mysore became ours, Lambton, whose talents had
become known to the Duke of Wellington on the voyage out, submitted to
him a plan for a survey, which was immediately recommended by Lord Clive,
Governor of Madras, to the Governor-General. Every care having been,
taken to verify the chain, it appeared that the utmost reliance could be placed
on its accuracy. It was made of blistered steel, and consisted of forty links
of two and a half feet each, being thus a hundred feet in all. The other
instruments were greatly out of order, but as well remarked by one ofthe most
distinguished modern Mathematicians, no man can ever be a practical philo
sopher who cannot bore with a saw and saw with a gimlet. Lambton having
little to choose from, and confident in his own unbounded resources, at once
set about surmounting the difficulties with the means at his command. In
selecting a locality for a base line, a surface as free of inequality as possible
is always resorted to, but as it is impossible to obtain a perfect level where it
is wanted, upright posts or pickets are driven into the ground, correct in
equalities. The first base line measured by Colonel Lambton commenced in
Lat. 12° 54' 64" N., near Bangalore, and extended 7° 43' 21" North-Easterly.
For each length of his chain twelve strong pickets, three inches in diameter,
hooped and shod with iron, were driven into the ground at intervals of about
eight feet from each other, on the top of each picket was placed a piece of
hard seasoned wood, eight inches in length and four in breadth, and over the
whole a strong planking of wood six inches in width and four in depth, the
whole being adjusted to the nicest possible level. On this the chain was lifted
by twenty people, so as to avoid all strain, and laid down with all the micros
copic precision that human skill and care permitted. The base line was
commenced on the 14th November 1800, a red letter day in the annals of
Indian Geodosy, and vyas completed in the extraordinarily short space of two
months, the triangulation A surveying technique in which the position of a network of points is determined by creating a series of triangles between them and measuring at least two of the internal angles and one side length. from its two extremities having been begun during
the middle of December. The following year a magnificent set of instru
ments were sent out from home, consisting of a 36 inch theodolite, and 18 inch
repeating theodolite, and a standard and brass scale by Cary. A 5 feet zenith
sector and two steel chains by Ramsden, with miscellaneous instruments of
lesser magnitude by various makers. The previous operations were consider-
ed rather tentative than permanent, and all the resources of science with the
most perfect appliances the age allowed were now taxed for the main base,