452 
NATURE 
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[Sepz. 17, 1885 
general geography, to an elaborately executed and artistic de- 
lineation of the topography of the country, and in some pro- 
vinces to the mapping of every field and individual property. 
Thus there have been three orders or classes of survey, and these 
may be respectively designated geographical, topographical, and 
cadastral ; all three have frequently been carried on fari passu, 
but in different regions, demanding more or less elaborate survey 
according as they happened to be more or less under British in- 
fluence. There is also the Great Trigonometrical or Geodetic 
Survey, by which the graphical surveys are controlled, collated, 
and co-ordinated, as I will presently explain. 
Survey operations in India began along the coast-lines before 
the commencement of the seventeenth century, the sailors pre- 
ceding the land surveyors by upwards of a century. The 
Directors of the East India Company, recognising the importance 
of correct geographical information for their mercantile enter- 
prises, appointed Richard Hakluyt, Archdeacon of Westminster, 
their historiographer and custodian of the journals of East Indian 
voyages, in the year 1601, within a few weeks of the establish- 
ment of the company by Royal Charter. Hakluyt gave lectures 
to the students at Oxford, and is said by Fuller to have been the 
first to exhibit the old and imperfect maps and the new and re- 
vised maps for comparison in the common schools, ‘‘to the 
singular pleasure and great contentment of his auditory.” The 
first general map of India was published in 1752 by the cele- 
brated French geographer D’Anyille, and was a meritorious 
compilation from the existing charts of coast-lines and itineraries 
of travellers. But the Father of Indian Geography, as he has 
been called, was Major Rennell, who landed in India as a mid- 
shipman of the Royal Navy in 1760, distinguished himself in the 
blockade of Pondicherry, was employed for a time in making 
surveys of the coast between the Paumben Passage and Calcutta, 
was appointed Surveyor of the East India Company’s dominions 
in Bengal in 1764, was one of the first officers to receive a com- 
mission in the Bengal Engineers on its formation, and in 1767 
was raised to the position of Surveyor-General. Bengal was not 
in those days the tranquil country we have known it for so many 
years, but was infested by numerous bands of brigands who pro- 
fessed to be religious devotees, and with whon Rennell came 
into collision in the course of one of his surveying expeditions, 
and was desperately wounded ; he had to be taken 300 miles in 
an open boat for medical assistance, the natives meanwhile ap- 
plying onions to his wounds as a cataplasm. His labours in the 
survey of Bengal lasted over a period of nineteen years, and em- 
braced an area of about 300,000 square miles, extending from the 
eastern boundaries of Lower Bengal to Agra, and from the 
Himalayas to the borders of Bandelkand and Chota Nagpur. 
ill-health then compelled him to retire from the service on a small 
pension and return to England; but not caring, as he said, to 
eat the bread of idleness, he immediately set himself to the uti- 
lisation of the large mass of geographical materials laid up and 
perishing in what was then called the India House ; he published 
numerous charts and maps, and eventually brought out his great 
work on Indian Geography, the ‘‘ Memoir of a map of Hindos- 
tan,” which went through several editions ; this was followed by 
his Geographical Syste u of Herodotus, and various other works 
of interest and importance. THis labours in England extended 
over a period of thirty-five years, and their great merits have been 
universally acknowledged. 
Rennell’s system of field-work in Bengal was a survey of routes 
checked and combined by astronomical determinations of the 
latitude and the longitude, and a similar system was adopted in 
all other parts of India until the commencement of the present 
century. But in course of time the astronomical basis was found 
to be inadequate to the requirements of a general survey of all 
India, as the errors in the astronomical observations were liable 
materially to exceed those of the survey, if executed with fairly 
good instruments and moderate care. Now this was no new 
discovery, for already early in the eighteenth century the French 
Jesuits who were making a survey of China—with the hope of 
securing the protection of the Emperor, which they considered 
necessary to favour the progress of Christianity—had deliberately 
abandoned the astronomical method and employed triangulation 
instead. Writing in the name of the missionaries who were 
associated with him in the survey, Pere Regis enters fully into 
the relative advantages of the two methods, and gives the 
trigonometrical the preference, as best suited to enable the work 
to be executed in a manner worthy the trust reposed in them by 
a wise prince, who judged it of the greatest importance to his 
State. “ Thus,” he says, “we flatter ourselves we have followed 
‘ 
the surest course, and even the only one practicable in prosecuting 
the greatest geographical work that was ever performed according 
to the rules of art.” 
What was true in those days is true still; points whose 
relative positions have been fixed by any triangulation of mode- 
rate accuracy present a more satisfactory and reliable basis for 
topographical survey than points fixed astronomically. Though 
the lunar theory has been greatly developed since those days by 
the labours of eminent mathematicians, and the accuracy of the 
lunar tables and star catalogues is much increased, absolute 
longitudes are still not susceptible of ready determination with 
great exactitude ; moreover, all astronomical observations, whether 
of latitude or longitude, are liable to other than intrinsic errors, 
which arise from deflection of the plumb-line under the influence 
of local attractions, and which of themselves materially exceed 
the errors that would be generated in any fairly executed 
nienatlaucE of a not excessive length, say not exceeding 500 
niles. 
Thus at the close of the last century Major Lambton, of the 
33rd Regiment, drew up a project for a general triangulation of 
Southern India. It was strongly supported by his commanding 
officer—Colonel Wellesley, afterwards the Duke of Wellington 
—and was readily sanctioned by the Madras Government ; for a 
large accession of territory in the centre of the peninsula had 
been recently acquired, as the result of the Mysore campaign, 
by which free communication had been opened between the east 
and west coasts of Coromandel and Malabar ; and the proposed 
triangulation would not merely furnish a basis for new surveys, 
but connect together various isolated surveys which had already 
been completed or were then in progress. The Great Trigono- 
metrical Survey of India owes its origin as such, and its simul- 
taneous inception as a geodetic survey, to Major Lambton, who 
pointed out that the trigonometrical stations must needs have 
their latitudes and longitudes determined for future reference 
just as the discarded astronomical stations, not however by direct 
observation, but by processes of calculation requiring a know- 
ledge of the earth’s figure and dimensions. But at that time the 
elements of the earth’s figure were not known with much exacti- 
tude, for all the best geodetic arcs had been measured in high 
latitudes, the single short and somewhat questionable are of 
Peru being the only one situated in the vicinity of the equator. 
Thus additional arcs in low latitudes, as those of India, were 
greatly needed and might be furnished by Lambton. He took 
care to set this forth very distinctly in the programme which he 
drew up for the consideration of the Madras Government, 
remarking that there was thus something still left as a desidera- 
tum for the science of geodesy, which his operations might 
supply, and that he would rejoice indeed should it come within 
his province ‘‘to make observations tending to elucidate so 
sublime a subject.” 
Lambton commenced operations by measuring a base line and 
a small meridional arc near Madras, and then, casting a set of 
triangles over the southern peninsula, he converted the triangles 
on the central meridian into a portion of what is now known as 
the Great Arc of India, measuring its angles with extreme care, 
and checking the triangulation by base lines measured at distances 
of two to three degrees apart in latitude. His principal instru- 
ments were a steel measuring chain, a great theodolite, and a 
zenith sector, each of which had a history of its own before 
coming into his hands. The chain and zenith sector were sent 
from England with Lord Macartney’s Embassy to the Emperor 
of China, as gifts for presentation to that potentate, who un- 
fortunately did not appreciate their value and declined to accept 
them ; they were then made over to Dr. Dinwiddie, the astronomer 
to the embassy, who took them to India for sale. The theodolite 
was constructed in England for Lambton, on the model of one in 
use on the Ordnance Survey ; on its passage to India it was cap- 
tured by the French frigate, the Dremon/aise, and Janded at 
Mauritius, but eventually it was forwarded to its destination by 
the chivalrous French Governor, De Caen, with a complimentary 
letter to the Governor of Madras. . 
Lambton was assisted for a short time by Captain Kater, 
whose name is now best known in connection with pendulum 
experiments and the employment of the seconds’ pendulum as a 
standard of length; but for many years afterwards he had no 
officer to assist him. At first he met with much opposition from 
advocates of the discarded astronomical method, who insisted 
on its being sufficiently accurate and more economical than the tri- 
gonometrical. But he was warmly supported by Maskelyne, the 
Astronomer-Royal in England; and soon had an opportunity 
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