Sept. 17, 1885] 
NATURE 
483 
of demonstrating the astronomical method to be fallacious, 
for its determination of the breadth of the peninsula in the latitude 
of Madras was proved by the triangulation to be forty miles in 
error. Still, for several years he never received a word of 
sympathy, encouragement, or advice either from the Govern- 
ment or from the Royal Society. A foreign nation was the first 
to recognise the importance of his services to science, the French 
Institute electing him a corresponding member in 1817. After 
this, honours and applause quickly followed from his own country- 
men. In 1818 the Governor-General of India—then the Marquis 
of Hastings—decided that the survey should be withdrawn from 
the supervision of a local Government and placed under the 
Supreme Government, with a view to its extension over all 
India, remarking at the same time that ‘he was ‘‘not aware that 
with minds of a certain order he might lay himself open to the 
idle imputation of vainly seeking to partake the gale of public 
favour and applause which the labours of Colonel Lambton had 
recently attracted ;” but as the survey had reached the northern 
limits of the Madras Presidency, its transfer to the Supreme 
Government, if it was to be further extended, had become a 
necessity. He directed the transfer to be made, and the survey 
to be called in future the Great Trigonometrical Survey of India. 
Noticing that the intense mental and bodily labour of conducting 
it was being performed by Lambton alone, that his rank and 
advancing age demanded some relief from such severe fatigue, 
and farther, that it was not right that an undertaking of such 
importance should hang on the life of a single individual, the 
Governor-General appointed two officers to assist him—Captain 
Everest, as chief assistant in the geodetic operations ; and Dr. 
Voysey, as surgeon and geologist. Five years afterwards Lambton 
died, at the age of seventy. The happy possessor of an unusually 
robust and energetic constitution and a genial temperament, he 
seems to have scarcely known a day’s illness, though he never 
spared himself nor shrank from subjecting himself to privations 
and exposure which even Everest thought reckless and unjustifi- 
able. These he accepted as a matter of course, saying little about 
them, and devoting his life calmly and unostentatiously to the 
interests of science and the service of his country. 
Everest’s career in the survey commenced disastrously. He 
was deputed by Lambton to carry a triangulation from Hydra- 
bad, in the Nizam’s territory, eastwards to the coast, crossing 
the forest-clad and fever-haunted basin of the Godavery river, 
a region which he described as ‘‘a dreadful wilderness, than 
which no part of the earth was more dreary, desolate, and fatal.” 
Indignant at being taken there, his escort, a detachment of the 
Nizam’s troops, mutinied, and soon afterwards he and his 
assistants, and almost all the men of his native establishment, 
were stricken down by a malignant fever; many died on the 
spot, and the survivors had to be carried into Hydrabad, whence 
litters and vehicles of all descriptions, and the whole of the 
public elephants, were despatched to their succour. To recover 
his health Everest was compelled to leave India for a while and 
proceed to the Cape of Good Hope, where he remained for three 
years. He availed himself of the opportunity to inspect Lacaille’s 
meridional are, which, when compared with the arcs north of the 
equator, indicated that the opposite hemispheres of the globe 
were seemingly of different ellipticities. He succeeded in 
tracing this anomaly to an error in the astronomical amplitude 
of the are, which had been caused by deflection of the plumb- 
line at the ends of the arc, under the influence of the attraction 
of neighbouring mountains. Thus he became aware of the 
necessity of placing the astronomical stations of the Indian ares 
at points where the plumb-line would not be liable to material 
deflection by the attraction of neighbouring mountain ranges. 
Shortly after his return to India Lambton died, and Everest 
succeeded him, and immediately concentrated his energies on 
the extension of the Great Arc northwards. He soon came to 
the conclusion that his instrumenta! equipment, though good for 
the time when it was procured, and amply sufficient for ordinary 
geographical purposes, was inadequate for the requirements of 
geodesy, and generally inferior to the equipments of the geodetic 
surveys then in progress in Eurepe. He therefore proceeded to 
Europe to study the procedure of the English and French surveys, 
and also to obtain a supply of new instruments of the latest and 
most improved forms. The Court of Directors of the Honourable 
East India Company accorded a most liberal assent to all his 
proposals, and gave him carte blanche to provide himself with 
- whatever he considered desirable to satisfy all the requirements 
of science. 
Everest returned to India with his new instrumental equipment 
in 1830, a year that marks the transition of the character 
of the operations from an order of accuracy which was sufficient 
as a basis for the graphical delineation of a comparatively small 
portion of the earth’s surface, to the higher precision and refine- 
ment which modern geodesists have deemed essentially necessary 
for the determination of the figure and dimensions of the earth 
asawhole. He immediately introduced an important modifica- 
tion of the general design of the principal triangulation, which 
up to that time had been thrown as a network over the country 
on either side of the Great Arc, as in the English survey and 
many others; but he abandoned this method, and, adopting 
that of the French survey instead, he devised a system of 
meridianal chains to be carried at intervals of about 1° apart, and 
tied together by longitudinal chains at intervals of about 5°, 
the whole forming, from its resemblance to the homely culinary 
utensil with which we are all familiar, what has been called the 
gridiron system in contradistinction to the network. The entire 
triangulation was to rest on base-lines to be measured with the 
new Colby apparatus of compensation bars and microscopes 
which had been constructed to supersede the measuring chain 
the Emperor of China had rejected; the base-lines were to be 
placed at the intersections of the longitudinal chains of triangles 
with the central meridional or axial chain, and also at the further 
angles of the gridirons on each side. Latitudes were to be 
measured at certain of the stations of the central chain, with 
new a‘tronomical circles in place of the old zenith sector, to give 
the required meridional arcs of amplitude. Two radical im- 
provements on all previous procedure were introduced in the 
measurement of the principal angles, one affecting the observa- 
tions, the other the objects observed. The great theodolites 
were manipulated in such a manner as not merely to reduce the 
effects of accidental errors by numerous repetitions in the usual 
way, but absolutely to eliminate all periodic errors of graduation 
by systematic changes of the position of the azimuthal circle 
relatively to the telescope, in the course of the complete series 
of measures of every angle. The objects formerly observed 
had been cairns of stones or other opaque signals ; for these 
Eyerest substituted luminous signals, lamps by night, and, by 
day, heliotropes which were manipulated to reflect the sun’s rays 
through diaphragms of small aperture, in pencils appearing like 
bright stars, and capable of penetrating a dense atmosphere 
through which distant opaque objects could not be seen. 
Everest’s programme of procedure furnished the guiding 
principles on which the operations were carried out during the 
period of half a century which intervened between their 
commencement under his superintendence and the completion 
of the principal triangulation under myself. The external chains 
have necessarily been taken along the winding course of the 
frontier and coast lines instead of the direct and more symmetri- 
cal lines of the meridians and the parallels of latitude. The 
number of the internal meridional chains has latterly been 
diminished by widening the spaces between them, and in two 
instances a principal chain has been dispensed with because, 
before it could be taken in hand, a good secondary triangulation 
had been carried over the area for which it was intended to 
provide. But these are departures from the letter rather than 
the spirit of Everest’s programme which has been faithfully 
followed throughout, first by his immediate successor, Sir 
Andrew Waugh, and afterwards by myself, thus affording an 
instance of the impress of a single mind on the work of half a 
century which is probably unique in the annals of India ; for 
there, as is well known, changes of personal administration are 
frequent, and are not uncommonly followed by changes of 
procedure. ; , 
The physical features of a country necessarily exercise a 
considerable influence on the operations of any survey that may 
be carried over it, and more particularly on those of a geodetic 
survey, of which no portion is allowed to fall below a certain 
standard of precision. Every variety of feature, of scenery, 
and of climate that is to be met with anywhere on the earth’s 
surface between the equator and the arctic regions has its analogue 
between the highlands of Central Asia and the ocean, which 
define the limits of the area covered by the Indian survey. 
Thus in some parts the operations were accomplished with ease, 
celerity, and enjoyment, while in others they were very difficult 
and slow of progress, always entailing great exposure, and at 
times very deadly. In an open country, dotted with hills and 
commanding eminences, they advanced as on velvet; in close 
country, forest-clad or covered with other obstacles to distant 
vision, they were greatly retarded, for there it became necessary 
