THE PHOTOGRAPHIC SURVEY

By Major E. O. WHEELER, M.C.

I had purchased a set of photo-topographical surveying instruments of the Canadian pattern, on behalf of the Survey of India, while on leave in 1920. A trial of this method of surveying mountainous country was to be carried out in Garhwal in 1921; but when Survey of India officers were asked for to accompany the Mount Everest Expedition, I was detailed to carry out the trial there. Possibly a word of explanation of the method used may not be amiss.

The “Canadian” method—if I may call it so; for although it was invented and has been used elsewhere, it has been far more extensively applied in Canada than in any other part of the world—may be briefly described as “plane-tabling by photography.” It requires, equally with the plane-table, an accurate framework, on which to base the detailed survey; and simply substitutes a small (3-inch vernier) theodolite and camera for the sight-rule and plane-table. Stations are fixed and photographs oriented by means of the theodolite; the photographs, which are taken so as to be as nearly as possible true perspectives, represent the country as it would be seen by the plane-tabler, and detail on them may be fixed by intersections or sketched in by eye in exactly the same way as on the plane-table.

Angles are read and photographs taken in the field; and, if considered necessary to test exposures or protect photographic plates from deterioration due to climatic conditions, development of plates is also carried out there. Otherwise, the map is made wholly in the office, using either contact prints or enlargements, from the negatives taken in the field. The latter are usually preferable. The main advantages at high altitudes over the plane-table are, that a much larger area can be covered in a given time in the field, that the instruments are more portable for difficult climbing, that there is no necessity to do accurate drawing with numbed fingers, and that the draughtsman may see the country from several points of view at one time. On the other hand, more equipment is necessary, and—a great disadvantage sometimes, as in this case—the map does not come into being as one goes along.

After carrying out various preliminary adjustments and tests at the office of the Trigonometrical Survey at Dehra Dun, I reached Darjeeling on April 30, and Tingri on June 19, travelling with Expedition Headquarters via Phari Dzong.

En route Tingri, we had caught glimpses of Everest and the neighbouring peaks; so that by the time we arrived there, I was able, with the help of the existing maps and what local information we had obtained, to decide on the area I would attempt to survey. I say “attempt,” for little was really known then about the geography, and still less about the weather conditions throughout the summer. As it turned out in the end, the area had to be much curtailed, and certain parts surveyed in considerably less detail than I should have liked: almost wholly on account of the weather. Although it was often fairly clear at 6 a.m. or so, photographs taken before 8, particularly at the latter end of the season, were of little use for surveying purposes.

However, at the outset, I had hoped to map, on the scale of 1 inch = 1 mile, the whole area between the Arun Gorge on the East and the Ra Chu on the West: and from the Nepal-Tibet boundary Northwards for some 20 miles; i.e. to the point where the various streams, flowing in a Northerly direction from the high boundary ridge, issue from the mountains proper into the more rolling foot-hills on the Southern outskirts of the Tibetan Plateau. This area includes Mount Everest itself near the centre of its Southern side, Makalu and Pk. 25,413 to the South-east, Pks. 23,800 (Khartaphu), 23,420, and 23,080 to the North-east and North, and Pks. 25,990 (Gyachung Kang), 25,202, 25,909 and 26,867 (Cho Oyu) to the North-west; and comprises some 1,000 square miles of country: a suitable season's work, given reasonably fine weather. This unfortunately we did not get.

On June 24, the day after Messrs. Mallory and Bullock had started for the Rongbuk Valley, Dr.Heron and I marched South across the plain to the village of Sharto, en route Kyetrak, in the Ra Chu Valley, where I intended to establish my base camp while surveying the Kyetrak Glacier and West face of the Cho Oyu—Gyachung Kang group. The next day we moved on to Kyetrak, 1 mile below the snout of the glacier, and made camp there. This bleak village and the route to it and over the PhÜse La have already been described.

June 26 was fine, so after crossing the Ra Chu on local ponies, ourselves and our ice-axes and rucksacks perched on Tibetan saddles—a cold and uncomfortable proceeding in the early morning—we ascended the 18,000-foot hill immediately West of the village. Up to 1 p.m. we had excellent views across and up the Kyetrak Valley; but only a glimpse of Gauri Sankar (Chomo Tsering) to the South-west, where heavy clouds soon began to roll up. Cho Oyu and Pk. 25,909 and their spurs unfortunately cut out all distant views to the South-east, as they did everywhere in the upper part of this valley; so that my first view of Everest was from Tingri a month later. Next day, we started shortly after daylight for a spur on the East side of the valley; unfortunately—and this happened in the case of almost every peak I started for until mid-September—clouds began to roll up, and we were forced to stop to take the photographs before we had reached a really good view-point.

Colonel Bury arrived at Kyetrak shortly after we got back to camp. On the 28th he and Heron started off early for a flying visit to the Kyetrak Glacier and Nangba La; I started later, after getting kit together, for a camp half-way up the glacier, and about 6 miles from Kyetrak. About 2 p.m. I found a comparatively dry spot on shale at 18,000 feet, and pitched my tents there, the last of the coolies arriving only at 6 p.m. The place was bleak enough, but was as far as I could get that day, and seemed suitable for two climbs—one on either side of the glacier.

My equipment consisted of the camera, theodolite, and a small plane-table—to help in identifying triangulated points—by way of instruments, which were carried by three coolies who remained with me. Ten other coolies slept at the base camp at Kyetrak, and carried stores up to me or moved the camp, as required; the camp consisted of a Whymper tent for the three coolies and a Meade for myself; bedding, food, a Primus stove and tin of kerosene for my own cooking, and yak dung fuel for the coolies. My servant remained at the base camp and sent up cooked meat and vegetables; otherwise I cooked for myself.

June 29 and 30 were useless days; but on July 1 the weather cleared a bit, and after crossing the glacier, I went up a sharp rock shoulder of Cho Rapzang. The peak was mainly loose granite blocks at a steep angle, so that progress was slow: it was noon when I reached the top (about 19,500 feet), and as I did so the clouds settled down, and it began to snow. However, at 4 p.m. it cleared sufficiently for some work to be done; after that we came down as quickly as possible in another blinding snowstorm, and reached camp just after dark; I for one very tired. I found the coolies exceedingly slow in coming down the loose blocks, I think because their balance was bad—they had to use their hands far more than I did.

I had a good view of the glacier from here: the East side is very steep and broken, with several tributary glaciers flowing down from Cho Oyu and Pk. 25,909, and from a 23,000-foot Peak (not triangulated) to the North of the latter. The West side, except for Cho Rapzang, round which the glacier flows, is a snowfield falling more or less gently from a low ridge running from the pass to the West of Cho Rapzang. The glacier itself is like many others in this region, moraine covered for 3 or 4 miles above its snout, “pinnacled” for another mile, and finally practically flat. But this flat portion gives by no means good going; when frozen it is very irregular and trying to walk over; and when thawed, is slushy and water soaked. There are two large water channels in the ice which are unpleasant to cross; these are from 10 to 15 feet wide and 20 feet deep, and carry a large volume of water in the afternoon. Crossing without a rope is distinctly dangerous, for although one can find places easy enough to jump, a slip would be certain death, for once in the channel it would be quite impossible to get out, or even to stop oneself on its smooth ice floor and sides.

Cloudy weather then set in; but on the 3rd I got a few photographs from a shoulder near by, and moved camp 2 or 3 miles farther up the glacier (at about 18,500 feet). I was in this camp for nine days and only succeeded in taking two low stations, one on either side of the glacier and each about 1½ miles from the pass (Nangba La) to Nepal; but the valley on the South side, leading down to Khungphu, turns sharply to the East just below the pass, and little could be seen of the Nepalese side. Each of these stations I went up twice—to wait all day long the first time, in each case, for weather which never came. To reach the station on the East side of the glacier I had the only comparatively difficult rock climbing which I met with during the course of the Expedition; and on the way down watched my theodolite coolie, whom I had left behind exhausted in the morning, tumble off a steep rock arÊte, theodolite and all; fortunately he jammed in a crack a few feet below, and was unhurt. During the day he had started up after us on his own, and had lost his way in the clouds.

On July 12—another wet day—I moved camp some distance down the main glacier and up a tributary flowing from Pk. 25,909 and Cho Oyu, and next day ascended a shoulder whence a good view into the cirque below these two peaks was obtained—or should have been obtained! But again I sat till dusk and saw little or nothing. Early the following day, however, it was fairly clear, so I got my photographs and then moved camp back to the base at Kyetrak.

The next three days were spent in moving my base camp to the bridge across the Ra Chu, 6 miles below Kyetrak; taking a light camp up to about 18,000 feet on the prominent hill immediately East of the bridge, climbing the latter, sitting through the usual storms without doing any work, and returning to the bridge. Time was getting on, and the weather was still bad, so I then decided to leave my camp at the bridge and move into Headquarters myself to get developing, etc., up to date, and have a short rest. I walked into Tingri, with two coolies, on July 18, and found Colonel Bury there alone: and the Headquarters house felt very comfortable indeed after a Meade tent, in spite of nightly pilgrimages from one dry spot to another, as the roof leaked!

Five busy days were spent at Tingri developing and printing; and as the weather showed little sign of improvement, I decided to go on with Headquarters to ChÖbuk, in the Rongbuk Valley and work on that side, so as to make sure of completing the most important part, in the vicinity of Everest, and return to the Kyetrak Valley if there should be time. So on the 24th Colonel Bury and I left Tingri and reached ChÖbuk on the 25th, where we met Mallory and Bullock, just in from their reconnaissance of the North and North-west sides of Everest. A talk with them gave me some idea of the country, and the view from an 18,000-foot hill above ChÖbuk enabled me to make a plan of campaign: far more extensive, as always, than the weather eventually allowed.

Colonel Bury, Mallory and Bullock had gone on to Kharta on July 26; on the 27th I moved up the right bank of the Rongbuk Valley some 10 miles, to the monastery, above which I took a 20,000-foot station the next day. The weather was dreadful, but at 6 p.m. I got a round of photographs, which really turned out very well considering the time of day at which they were taken: it took me four and a half hours to get up this peak—fresh snow and scree—and although I had no glissades, only half an hour to come down.

On the 27th I moved camp to a grassy hollow near the snout of the glacier—Mallory and Bullock's base—and next day occupied another hill overlooking the main glacier and valley, and looking up the side valley on the East, which joins the Dzakar Chu just below the glacier snout. The next three days were spent in establishing a light camp on the left bank of the East branch of the Rongbuk Glacier, about 3 miles from its snout, and taking a station on its left bank to overlook both the East and main glaciers.

The Rongbuk Glacier is made up of two large branches, one flowing from the snow basin immediately below the great North wall of Everest, and the other, the “West Rongbuk” which joins the main stream about 4 miles above the snout of the glacier, flowing East in the basin between the high North-west ridge of Everest and the South-east slopes of Pk. 25,990 (Gyachung Kang). At one time there was a third branch, the “East Rongbuk,” which must have also joined the main stream, but this has receded until its snout is now a mile or more East of the main glacier, and only its torrent pours into a large cave in the latter. The East Rongbuk itself consists of two branches: one, the more southerly, flows from the great snow basin (which we eventually crossed to reach the North Col) between Everest, its North Peak and Col, and Pk. 23,800 (Khartaphu); and the other, which joins the South branch about 2 miles from its snout, from between Pks. 23,800 and 23,420. The former gives a 20,000-foot pass, very steep on the South side, to the Kama Valley; and the latter, an easy pass of about the same height to the head of one branch of the Kharta Valley.

I camped, at about 19,500 feet, on the moraine-covered glacier opposite the junction of the northerly branch from Pks. 23,800 and 23,420. On the way up I followed the watercourse between the ice of the Main Rongbuk Glacier and the scree and conglomerate slopes to the East of it, as far as the mouth of the East Rongbuk stream (3 miles), which gave good though boulder-strewn going. Thence a short scramble up “cut-bank” on the right bank of the East Rongbuk stream to the shelf of an old lateral moraine of that glacier, and along the latter—excellent going—to near its snout. The stream is pretty big in the evening; but quite easy to cross—except for iced rocks—in the early morning: and from there I followed up a series of lateral moraines on the left bank, to my camp. It was not till I was coming down that I discovered that the moraine-covered glacier itself—here covered with shale instead of boulders and scree as in the case of the main glacier—gave comfortable walking.

A little distance below my camp site, the moraine-covered snout gives place to pinnacled ice, divided into three sections by two broad, shaly medial moraines. Either of the latter would be very suitable for a camp, and would give an excellent route to our 21,500-foot camp below the Chang La. The latter might, I think, be reached by this route in three days from the base camp at the snout of the main glacier, camping the first night at 19,000 feet at the start of the medial moraine, the second at 20,000 feet on the medial moraine some 2 miles above the junction of the Northern and Southern branches of the East Rongbuk, and the third night on snow at 21,500 feet below the North Col. The better moraine to ascend would require reconnaissance; for the pinnacles between them are difficult and slow to cross. The valley sides are steep in the lower reaches of the glacier, but more shaly and gentle on both branches, above their junction.

August 3 broke clear; and I started up a likely looking peak behind (South of) camp, which appeared to be on the ridge between the East and main glaciers. I afterwards found that this was not the case; at the time I had to stop on a lower point as the clouds settled down. From here I had a glimpse of a big peak—Makalu, I thought—over the pass at the head of the southerly branch of the glacier: and this gave me the idea that there must be a comparatively low pass from here to the Kama Valley. But clouds prevented me seeing more and studying the topography more carefully. There were heavy snowstorms on August 4 and 5, but the 6th looked better, and after four hours' most strenuous step-cutting up and slithering down pinnacles, I crossed the glacier and ascended a 21,000-foot station on the other side, from which I obtained good, if cloudy, views of the East Rongbuk Glacier. Snow in the night and a dull morning made me decide to abandon this area—I could get my camp no farther up owing to having insufficient warm clothes to camp all my coolies at this height—and I returned to the base camp, preparatory to tackling the West side of the Rongbuk Valley. Six hours' easy going took me to my base camp.

After two days' rest and office work, I crossed the glacier and put a light camp at about 19,000 feet in a small hanging valley below the “Finger,” a black rock gendarme which is a very prominent landmark on the left bank of the Rongbuk Valley. On August 11 it snowed heavily, and I found my bed, in which I spent the day, very hard indeed—the camp being pitched on large boulders on top of the moraine. On the 12th, 13th, and 14th, I started for the “Finger,” the first time by the ridge immediately above camp, which gave some nice climbing with the rocks partly snow covered as they were, and the other two days, by a much quicker but less interesting route up soft snow and scree. Each day the clouds came down, and although I waited till nearly dark at about 20,500 feet on the ridge, it was not till the third day that I got a round of indifferent photographs.

Time was getting on, so on the 15th I called my “Finger” station “good enough” and moved camp up the left bank of the main glacier to a point on the old lateral moraine, opposite the entrance of the stream from the East Rongbuk; and the next day round the corner to the West, some distance up the West Rongbuk Glacier, and about 1,000 feet above it. En route, I tried to get some photographs from the high moraine at the junction of the West with the main glacier; but again the weather defeated me, and I got into camp—another uncomfortable one—soaked to the skin.

I was in this camp for five days; most of them spent huddled under rocks waiting for the clouds to lift. I had one beautiful day, my only one in six weeks, and got some very nice photographs of Mount Everest and its West ridge. It is surprising how a little good weather and the feeling of having really done some work affects one's spirits!

On August 21 I moved back to my base camp at the glacier snout, again trying for a station at the corner—and failing. I had not done nearly as much as I wanted to do; but there seemed to be no end to the bad weather, and only a month or a bit more remained in which to map the whole of the East side of the mountain: and I had heard from Colonel Bury that there would be a considerable amount of work on that side. Originally, I had hoped not only to return to the bridge over the Ra Chu to complete the work in the Kyetrak Valley, but also to take several stations in the valleys running North from the 23,000-foot group North of Everest. But again apart from shortage of time, the weather made it out of the question, and I went through to Kharta, via the Doya La, arriving there on August 27.

The change in scenery immediately one crosses the Doya La is most marked, both as regards rock and vegetation. The former—mostly gneiss—is far more rugged and interesting, and there is infinitely more of the latter. The Headquarters camp at Kharta, in a little poplar grove, was pleasant indeed after the bleak, uninteresting Rongbuk Valley; and I thoroughly enjoyed my five days there, developing and printing; busy days, but very different from lying on one's back on the sharp boulders of the Rongbuk moraines. Mallory, Bullock and Morshead were in Kharta when I arrived; Colonel Bury and Wollaston returned from their excursion to the Popti La soon after, and Raeburn arrived on September 1. It was a great treat to me to be able to “swap lies” with so many people, after two months almost wholly alone!

On September 3 Morshead and I started up the Kharta Chu in the wake of Mallory and Bullock, who had gone up to get the “bundobust” for the final fling going. As usual, bad weather dogged my footsteps, and although the weather while I was in Kharta had been glorious, Morshead and I spent seven days in taking two very indifferent stations in the lower part of the Kharta Valley, before joining the remainder of the expedition at the “Advanced Base” on September 11. A further eight days were spent there, waiting for the weather; but in that time I was able to get two very useful stations, one on either side of the valley.

On September 19 I moved up to “No. 1 Camp” with Mallory, Bullock and Morshead; and shared the fortunes of the rest of the Expedition as far as Kampa Dzong on the way back to Darjeeling, where Raeburn, Heron and I left Headquarters to return to Darjeeling via Lachen and the Teesta Valley. I was delighted to get into the “final push,” and enjoyed the few days' change from surveying to climbing, enormously; except that I felt the cold very much in my feet, and had it not been for Mallory's good offices—he rubbed my feet for a solid hour after we came down from Chang La—I feel sure that the result might have been much more serious than the slight discomfort I afterwards experienced.

I took three stations in the neighbourhood of No. 1 Camp—one on either side of the Kharta Glacier, and one at 22,300 feet on the “Lhakpa La.” This was on snow, with my instrument resting on, and steadied by, bags of “tsampa”; which proved to be a most excellent substitute for rock!

On September 26 I crossed with Colonel Bury and Wollaston to the Kama Valley; unfortunately, we only had two clear days there, and I had to leave it without covering as much ground as I should have liked, though—as usual—I spent my days in snowstorms, hoping for breaks in the clouds.

The return to Darjeeling via the Serpo La, Lachen, and the Teesta Valley, made a pleasant change from the Phari route; but again bad weather spoiled our views, and we saw nothing at all of Kanchenjunga and its neighbours. Raeburn went in by the usual road via Gangtok; Heron and I followed the river—an excellent route in spite of the prevalence of leeches—and reached Pashok on October 19. Heron went on to Darjeeling, a further 18 miles, the same day. I followed on the 20th.

I enjoyed the Expedition and my work with it, thoroughly; but in my opinion, Tibet, at any rate that portion of it in which we were, is a place to have been, rather than one to go to!