The Great Arc (17 page)

With the two great Astronomical Circles reinforced and installed in specially built observatories, Waugh at Sironj and Everest at Kaliana (near the northern end of the Arc but sufficiently removed from the mountains to eliminate their ‘attraction’) laboured simultaneously on forty-eight consecutive nights in December and January 1839–40 to observe some thirty-six pre-selected stars every night. In 1840–1 the same procedure was followed at Bidar and Sironj. So satisfied was Everest with these two sections of the Arc that he was pleased to note that there were now ‘no two elements in nature more definitively known’.

Simultaneous observations of the same stars using identical
instruments and procedures was the surest way of getting precise comparative latitudes. From the grand total of over three thousand stellar observations, the latitudes of Bidar, Sironj and Kaliana were calculated to three decimal points of a second of a minute of a degree. The length of the Arc could now be deduced to the same standard of accuracy, and this value then correlated with the distance as computed by triangulation to obtain the ‘amplitude’ of the Arc.

In various reports and submissions Everest devoted reams of handwritten sheets to explaining his methods, to dilating in minute detail on the problems of refraction, plummet attraction and astronomical observation, and to recording his findings. A new set of constants – ‘Everest’s 2nd Constants’ – were issued and showed that a semi-diameter of the equator at nearly twenty-one million feet exceeded the northern hemisphere’s diameter by exactly 67,260 feet. The compression of the poles in terms of the diameter of the equator was thus 1:311.044.

But
cui bono?
indeed. Basically it was all numbers, page after page of angle tables and thirty-line equations involving every logarithmic device and geometrical formula known to mathematics. ‘He undervalues everything that is not abstruse,’ complained Sir Henry Lawrence, then a rising star in the administrative firmament. Instead of surveying India, the Surveyor-General sought only ‘to astonish the savants of Europe’. The government wanted maps, or at least the coordinates for all Everest’s trig stations on which they could be based. To them, as to most other people, all the rest was just too esoteric and too incomprehensible.

It was also too impermanent. Revisions seemed to go on indefinitely. At the mention of a new value for, say, refraction, or a new calculation of the co-ordinates for Madras, the whole thing required re-adjustment. The advent of the electric telegraph in the 1860s, and the opportunity this would provide for synchronising observations and so obtaining much more accurate readings for longitude, would constitute a veritable
revolution in cartography and again necessitate extensive revision.

When in 1843, with the Arc completed, Everest finally put Hathipaon on the market and, embracing retirement, headed home, the Great Trigonometrical Survey was going from strength to strength. More regions, notably in what is now Pakistan, came under British rule and necessitated more chains of triangles. But of the Great Arc and its champion few traces would remain. ‘No scientific man ever had a greater monument to his memory than the Great Meridional Arc of India,’ wrote Sir Clements Markham, President of London’s Royal Geographical Society; it was ‘one of the most stupendous works in the whole history of science’. Yet for a total expenditure of about £150,000 the Great Arc had left precious little to show for itself. Sixteen weather-streaked towers still dotted the Doab, three largely deserted observatories in out-of-the-way places remained to puzzle the passing traveller, and atop a variety of
droogs
, hills and mounds several hundred station markers slowly succumbed to the combined assault of climate, vegetation and local prejudice.

Lambton’s uninviting reports survive only in the dusty pages of
Asiatick Researches
, while Everest’s two published accounts, though heavy and handsome, were poorly distributed and soon superseded. They are now unobtainable in all but a few specialist libraries. Much the most eloquent testimony to his life’s obsession lies in the ruined shell of Hathipaon on its ridge above the Dun. There he spent his last years in India, dreading the health risks of a return to the plains, working on his reports and tables, and overseeing the operations of his subordinates. From the likes of Joshua de Penning in Calcutta, of Joseph Olliver and William Rossenrode, he now enjoyed the regard and affection which he had so often forfeited.

Both Rossenrode and Olliver had retired as soon as the Arc was finished but, with their sons and sons-in-law established in the Survey, they remained in close touch. As for old Joshua
de Penning, the one-time incompetent and traitor, he had become ‘my dear old friend’. De Penning would outlast even Everest, not retiring until 1845. In a letter from Calcutta of 1841 he fusses over Everest’s health much like a loyal family retainer, and sends ‘merino vests and drawers, a dozen of each … packed up in four tin cases, which I hope will reach you in time for the cold season’. If Hathipaon has a ghost, he may be sporting woolly underwear. Perhaps, chanting logarithms from a windowless socket in what was once the drawing room, he gazes on the roofs of the Survey’s Dehra Dun offices and then, swivelling like a theodolite, fixes unerringly on the spot known as Arcadia. With Hathipaon at the apex, the site of his terminal base-line on one side and the Dehra Dun headquarters of the Survey on the other make as neat and evocative a triangle as any in India.

I
n the mid-1830s, while Everest and Waugh had been putting the finishing touches to the Great Arc, four other parties from the Great Trigonometrical Survey had begun work on the ‘bars’ of Everest’s cage-like ‘grid-iron’ of triangulation. In the 1840s, with the Arc complete, all resources were switched to this grid-iron and elaborate plans laid for its extension throughout the subcontinent.

Lambton’s ‘cobweb’ of triangles in the south, though less neat and systematic than a grid, had provided the desired scatter of precisely located trig points from which cheaper topographical surveys could plot the detail needed for maps. The grid-iron was designed to furnish the same control for the rest of India, but with the trig points being arranged in ‘bars’ of triangulation.

A less contentious analogy was sometimes drawn from nature. Envisaging the north – south Great Arc as a tree-trunk, and its east – west limbs (like the Bombay and Calcutta longitudinal series) as branches, a tracery of slender fronds festooned with triangulated foliage (the ‘bars’ of the ‘grid-iron’) were to be superimposed on the subcontinent. Extending outwards from the Arc, the shade of their branches would define what the British deemed to be India in terms more organic (and so capable of further growth) and more congenial to tender consciences.

The immediate priority was to extend the control afforded by trigonometrical surveying to that part of northern India,
the heartland of British rule, between the Great Arc in the west and Calcutta in the east. Joseph Olliver’s seven-hundred-mile longitudinal series from Sironj to Calcutta, the one conducted during Everest’s absence in England, provided the branch. Striking off from it at right angles, each ‘bar’ or ‘twig’ was to run north, roughly parallel to the Great Arc and at intervals of one degree longitude apart. With the Great Arc on the 78-degree meridian and Calcutta on the 89th, that meant eleven meridional series. Those at either end could be extended up into the Himalayas in the west, in the now British territories of Garhwal and Kumaon where Hodgson and Herbert had operated, and, in the east, into the Kingdom of Sikkim whose ruler permitted limited access to the area around Darjeeling. But for the most part the ‘bars’ terminated on the Nepal frontier, whence all approaches to the central Himalayas were still refused by the Kathmandu government.

With the exception of these extremities, the terrain over which the new tracery extended was that of the flat, densely populated and, in those days, generously shaded Gangetic plain. Here, because of the difficulties encountered by Everest with his flares and scaffolds, smaller triangles with shorter sides than those of the Great Arc were acceptable; but sight-lines had still to be laboriously ascertained and cleared, and innumerable stumpy towers erected. Nor was the work any less perilous. On the Nepal frontier, in the dreaded
terai
where Robert Colebrooke had once been stricken with malaria, whole survey parties now shared his fate. The death toll amongst both British and Indians sometimes reached three figures in a single season. The danger, wrote Clements Markham of the Royal Geographical Society, was ‘greater than that encountered on a battle-field [and] the per-centage of deaths larger; while the sort of courage … required was of a far higher order’.

Casualties in the
terai
attended not just the eleven south – north series, which terminated amongst its wooded swamps
and grasslands, but also a west – east series which, connecting the heads of the eleven meridional ‘bars’, was carried right through the
terai.
Known as the North-East Longitudinal series, it corresponded to Olliver’s Sironj-Calcutta series at the southern end of the ‘bars’. It would link their northern extremities by way of a 750-mile chain of triangles which ran parallel to the Himalayas from Everest’s base-line in the Dun all the way to Assam.

Uniquely, the North-East Longitudinal was not, however, the work of one man or one party. None could have survived so many consecutive seasons exposed to its lethal conditions. Instead, each of the grid-iron’s survey parties, having carried their triangles north to form one of the ‘bars’, then turned left to connect it up with the top of the next ‘bar’ one degree to the west. The North-East Longitudinal was thus pieced together over many years as each of the ‘bars’ was completed. It formed, as it were, the topmost branch of the whole tree. And in its carefully triangulated trig stations running along the base of the Himalayas there lay the long-awaited certainties from which the heights of the snowy peaks might at last be confidently observed.

Piling up the metaphors, Everest and then Waugh, his successor as Superintendent of the Great Trigonometrical Survey and Surveyor-General, conceived this Gangetic grid, or segment of the tree, as a quadrilateral. The ‘bars’ were contained within four sides consisting of the Great Arc itself, its two longitudinal branches (the Sironj-Calcutta series and the North-East Longitudinal) and an upright series linking them in the east known as the Calcutta Meridional. At each corner of this quadrilateral, accuracy was ascertained by a base-line measurement with the compensation bars. The bases at Calcutta, Sironj and the Dun had, of course, already been conducted by Everest himself. To complete the quadrilateral it remained only for Waugh to measure a fourth base-line in the far north-east.

The Himalayas

The site chosen was at a place called Sonakhoda, below the Darjeeling hills where the North-East Longitudinal intersected the meridional upright carried up from Calcutta. There, in the moist plains of northern Bengal, Waugh and his assistants assembled with the compensation bars in late 1847. As with the Dun base-line, connection to the primary series, in this case the North-East Longitudinal, was made via stations on the neighbouring hills. It was while choosing and linking these, in the latter half of 1847, that Waugh found a new contender for the title of the world’s highest mountain and so reopened the debate about the height of the Himalayas.

Everest himself had taken little interest in the subject. From the back door of Hathipaon he had been confronted by as fine a panorama of glistening summits as any in the world. They were good for the soul, but to his life’s work on the Great Arc they were peripheral. From The Chur he may have actually sighted Nanda Devi; but there is no record of his having attempted to verify its height. Bagging mountain peaks was not his business. For those who had pursued the subject, often with inferior instruments and speculative observations, he felt only contempt.

Waugh, too, was circumspect on the subject. Although it was obvious that from the North-East Longitudinal series the secrets of the high peaks were within range, there was to be no unseemly rush to plot them. It was the sort of thing to which a surveyor might usefully devote his spare time while, say, waiting for towers to be built or trees cleared. Nor, when the peaks were indeed plotted, would there be any urgency to make public the results. The Survey had its code about publication, and no findings could be announced before exhaustive computation and revision of the data on which they rested.

The peak to which, almost casually, Waugh directed his theodolite while plotting the connection of the Sonakhoda base-line was Kangchenjunga, now perhaps the most easily
observed of all the Himalayan giants and the third highest in the world. At the time Nanda Devi at the other end of the main Himalayan chain, the ‘A2’ of Hodgson and Herbert, was still credited with the greatest elevation yet measured. Webb’s Dhaulagiri also had its champions, although the 28,000 feet once suggested for it by Henry Colebrooke had long since been dismissed as wildly improbable; something rather less than Webb’s own estimate of 26,862 feet was thought more likely. In fact, it looked as if five vertical miles (26,400 feet) might constitute a pre-ordained ceiling above which no part of the earth was meant to protrude.

Waugh and Kangchenjunga now proved this wrong. But anyone who has seen Kangchenjunga loom from the clammy cloud-cover which envelops most of the eastern Himalayas for most of the year will find Waugh’s encounter deeply unsatisfactory. A skilled and devoted professional, he lacked Everest’s charisma and seemed content to live in his guru’s shadow. Some found him sanctimonious; but if he did not endear himself to his subordinates, neither did he aggressively antagonise them. Fair to his mountains as to his men, Waugh eschewed comment as resolutely as Everest embraced it. Instead of penning narratives, he filed reports.

From above the hill resort of Darjeeling the dawn observer who is lucky enough, like Waugh, to beat the mist as it wells up from the Rangit valley enjoys one of nature’s greatest spectacles. Forty miles away, across a chasm lined with rhododendrons and bubbling with cloud, the mountain stands detached from the ground and seems not of this world. Rather does it materialise, ghost-like, out of the lightening sky. You look for it on the horizon and find that you have been staring into its navel. The summit, cleft by a wall of granite and defined by its glistening flanks, sails high overhead like a celestial Olympus etched in chill sunlight.

‘The western peak of Kangchenjunga attains an elevation of no less than 28,176 feet above the sea, which far exceeds
what has hitherto been conjectured,’ wrote Waugh in ink as dry as dust. He and his assistants, including William Rossenrode junior, had observed it from Tiger Hill, Senchal, Tonglu and most of Darjeeling’s other now renowned viewpoints. It was much the highest known mountain in the world, being nearly three thousand feet in excess of Nanda Devi. And since it had been approached more closely than any of its rivals, and from a base-line subject to the rigorous controls of the Survey, the observations could be taken to be unassailably accurate. Though incidental and unexpected, Kangchenjunga’s primacy could be seen as a crowning triumph for the Great Arc.

Yet Waugh did not announce this discovery until two years later. Even then he did so only in an internal memorandum; for doubts had arisen, not about Kangchenjunga, but about another peak to which, from Darjeeling, he had also taken bearings. The bearings did not include vertical angles because the peak in question was deemed too distant and indistinct. Like other such irregularities on the horizon, its position was plotted, its profile sketched, and it was then given a sequential designation. Waugh used the letters of the Greek alphabet. The distant peak, lying to the left of Kangchenjunga and at least 120 miles away on the Nepal – Tibet border, became ‘gamma’; and although loath to admit it, he already suspected that ‘gamma’ might exceed Kangchenjunga.

Waugh conducted his Darjeeling observations in November 1847. In the same month, but from the North-East Longitudinal at Muzaffarapur in Bihar, John Armstrong, one of the many assistants recruited by Everest, had taken three sets of horizontal angles and one vertical angle to a shy and partly obscured giant which, as Waugh immediately suspected, proved to be the same mountain as ‘gamma’. Armstrong had listed his peak simply as ‘b’; and from his angles, a height of 28,799 feet seemed to be indicated. But ‘on account of the great distance’, Waugh distrusted Armstrong’s observations as much as his own. He decided to await the outcome of the
1848–9 season. ‘I particularly wish you to verify Mr Armstrong’s peak “b”,’ he told John Peyton, once one of Everest’s prized ‘computers’. ‘His [Armstrong’s] peak “a”,’ Waugh added, ‘also requires to be well verified because the two heights deduced are very discordant.’ Almost certainly, this ‘a’ was Makalu, today reckoned to be 27,805 feet and so the fourth highest in the world. It stands on the Nepal – Tibet frontier just to the east of a cluster of giants including the timid fang which was Armstrong’s ‘b’ and Waugh’s ‘gamma’.

Peyton had no joy in 1848–9. The peaks were visible only in the early mornings and only during November and December. Of a morning, by the time his instrument had been trained on them, they had disappeared; and of a season, by the time his survey towers had been built, the peaks had gone into hibernation behind a veil of cloud which lifted not even at daybreak. Primarily concerned with contributing his section to the North-East Longitudinal, Peyton found it impossible to have towers ready early enough in the season for mountain triangulation.

A year later, with more encouragement from Waugh, James Nicholson succeeded Peyton and resumed the quest. Edging east, the North-East Longitudinal took Nicholson slightly closer to the target. His ‘sharp peak “h”’ was clearly Armstrong’s ‘b’ and Waugh’s ‘gamma’, and he concentrated his attentions on it. Numerous angles, both vertical and horizontal, were taken, six of which were used in the final computations. But although Nicholson himself must have known the outcome by early in 1850, Waugh was in no hurry to proclaim it.

All the Himalayan peaks were first given new designations, this time in Roman numerals from I to LXXX. ‘Gamma’/‘b’/‘h’ now became Peak XV. Waugh then, in the words of Reginald Phillimore, the Survey’s historian, ‘asked the Chief Computer in Calcutta to revise the form [formulae?] for computing geographical positions of snow peaks at distances of over 100 miles’. The Chief Computer was Radhanath Sickdhar, the
Bengali genius whose arithmetical wizardry had so impressed Everest. A later tradition, dismissed by Phillimore although accepted by many Indian historians, that it was in fact Sickdhar who first realised that XV was the world’s highest presumably stems from this reference. The popular account of the excited Bengali rushing into Waugh’s office exclaiming that he had ‘discovered the world’s highest mountain’ is obviously rubbish. Waugh’s office was in Dehra Dun while Sickdhar was now in Calcutta. But it is quite probable that Sickdhar’s computations provided the first clear proof of XV’s superiority.