the meridional line which had been traced through England should be followed northwards through Scotland to the Shetland Islands. On this being done, the French and English arcs together would stretch over upwards of 20°. These were great conceptions, and the operations for their realisation increased in difficulty the farther northwards they were extended. They not only required great skill in scientific observations, but the employment of immense personal energy. Captain, afterwards Colonel Colby, had by this time been long associated with Colonel Mudge in the survey, and possessed all the qualifications necessary for its delicate but arduous duties.

By the year 1817 the triangulation had been extended as far north as Aberdeen, near which, on the Belhelvie Sands, was measured the only base-line measured in Scotland. The triangles included the whole country northwards from Cumberland, embracing the Isle of Man and part of the coast of Ireland. In 1819, the year in which Drummond and Colby became acquainted, the latter had commenced operations north of Aberdeen, his "head-quarters" in the beginning of the season being placed on Corrie Habbie, a mountain in Banffshire. The survey officers were by this time a numerous and important body. Besides the staff employed in the work of triangulation and base measurements, there was another employed in filling in the spaces within the larger triangles by a system of smaller ones, and yet another employed as draughtsmen in embodying in maps the results of the measurements and calculations. The permanent head-quarters of the service were established at the Tower in London, where all the necessary offices for the work were provided. During the summer and

autumn months the officers engaged in the measurements were in the field or on the mountain. In winter they were quartered in London, engaged in calculations and in improving the apparatus employed in the survey.

The life of the officers who went "out" in the surveying season was an exceedingly trying one. It was a life of hardship and exposure; of frequent privation and fatigue; occasionally of hazard and adventure; a life to try the strongest, and certain to injure the less robust. The duties were twofold-station-hunting, and the work of observation. A country was to be rapidly traversed-for every day in the season was of valueand hill after hill to be ascended till the most eligible for a station of observation was discovered. The station was always on a hill top or mountain peak. The observatory once erected there, the officers made it their home; some of them made expeditions thence for the purpose of erecting flag-staffs on the hills as points for observation; while others, through all weathers, kept by the theodolite, ready to avail themselves of every favourable opportunity of observation. There is an admirable account of a surveying season in the Highlands in a letter from Major Dawson to Lieutenant-Colonel Portlock, published in extenso in Portlock's "Memoir of Colonel Colby." It was the season of 1819, from which Colby was just returning, when Drummond became acquainted with him. As germane to my present purpose I cannot refrain quoting here some extracts from this letter. In describing Colby's life in one surveying season, it describes the life which Drummond led for several seasons in "station-hunting" and the work of observation on mountains; and is all the more valuable as, during the years when he was leading this sort of

life, we have but few and far between glimpses of him.

With great labour and difficulty Colby, accompanied by his assistants, Robe and Dawson, and a selected party of artillerymen, established themselves and instruments in camp on the top of Corrie Habbie, in Banffshire, a hill about 2200 feet high, and in the centre of a mountainous country-Benrinnes, the Monagh Lea, the Cairngorms, and Ben Macdui being all in view. Here for some time Colby devoted to the work of observation every favourable moment from sunrise to sunset. In the intervals he instructed his assistants in the use of the instruments. Though the month was June, it was far from being summer weather on the Corrie. On the 28th June they experienced a tremendous storm of hail, which covered the ground with a coating several inches deep in a few minutes. "After this fell snow for an hour or so, and then sleet and rain. We were forced to be out shovelling the hail and snow from the tents while the storm lasted, and when it was over the men set to snow-balling one another as a means of warming themselves a rather unusual amusement in the latter end of June." This was Dawson's first season on the mountain tops, and he made notes at the time of facts which must have afterwards become common-place to him.

Tuesday, 29th June.-Captain Colby took Robe (Lieutenant) and a small party of the men on a station-hunt,' or pedestrian excursion, to explore the country along the eastern coast of Inverness-shire, Ross-shire, and Caithness, and to erect objects upon some of the principal mountains, and select those which, from their position and circumstances, should be preferred for future encampments. That particular season of the

year was usually taken for the purpose, because, owing to the tremulous state of the atmosphere, it is unfavourable for instrumental observations, except occasionally for an hour or so after sunrise, and for a like period before sunset; at which times, unless the summit of the mountain chances to be free from clouds and mist, nothing really valuable, in the way of observation, can be done. The opportunities afforded for the purpose are indeed extremely capricious and uncertain at other times also. It was no uncommon occurrence for the camp to be enveloped in clouds for several weeks together, without affording even a glimpse of the sun or of the clear sky during the whole period; and then in a moment the clouds would break away or subside into the valleys, leaving the tips of the mountains clear and bright above an ocean of mist, and the atmosphere calm and steady, so as to permit the observations, for which the party had waited days and weeks, to be taken in a few hours.

"Wednesday, 21st July.-Captain Colby and Robe returned to camp, having explored all the country along the eastern side of the counties of Inverness, Ross, and Caithness, as well as the Mainland of Orkney, and having walked 513 miles in twenty-two days.

"Friday, 23d July.-Captain Colby took me and a fresh party of the soldiers on a station-hunt, to explore the country to the westward and northward of west. Our first halting-place was to be Grantown, at a distance of twenty-four miles, and Captain Colby having, according to his usual practice, ascertained the general direction by means of a pocket-compass and map, the whole party set off as on a steeple-chase, running down the mountain-side at full speed, over Cromdale, a mountain about the same height as Corrie Habbie, crossing several beautiful glens, wading the streams which flowed through them, and regardless of all difficulties that were not absolutely insurmountable on foot. Sometimes a beaten road would fall in our course, offering the temptation of its superior facilities to the exhausted energies of the weary members of our party; and in such cases freedom of choice was always allowed them. Captain Colby would even encourage such a division of his

party, and the spirit of rivalry which it induced, and took pleasure in the result of the race which ensued. Arriving at Grantown in about five hours and a-half, we dined there, and proceeded afterwards along the valley of the Spey by the high road to the Aviemore Inn to sleep. The distance travelled by us that day was calculated at thirty-nine miles.

"Saturday, 24th July.-Started at nine o'clock. I was dreadfully stiff and tired from the previous day's scramble, and with difficulty reached Pitmain (thirteen miles) to dinner.

Garviemore Inn, distant eighteen miles, was to be our next stage, and I really thought it was more than I could accomplish that day; but Captain Colby said it was not. It was his intention, however, to leave the beaten road immediately, and crossing a rough, boggy tract of country to the northward, to gain the summit of Cairn Derig, a mountain about 3500 feet high, and about ten miles distant, and having built a large pile of stones upon it, to proceed again across the country to Garviemore. [Dawson thought this quite beyond his powers, but Colby insisted it was not, and he had to proceed.] I kept pace with him throughout the remainder of the day, and arrived at the inn at half-past eleven o'clock at night, much more fresh than at the end of our first stage the day before. The distance travelled that day was forty miles. "Sunday, 25th July.-There being no church, we strolled out soon after breakfast to see the country. From the opposite side of the road, to the southward, the ground rises suddenly to the height of about 1500 feet. This we ascended, and found, as is frequently the case, an eminence of greater elevation behind it. Having gained this second elevation, a third appeared, and so on to others in succession, though frequently in pursuing our straight course we had to descend rocky valleys, and thus to lose in a quarter of an hour the elevation which it had cost half an hour's severe climbing to attain. In this way, however, we at length reached the summit of Bui-Annoch, a mountain rising suddenly from the wooded shores of Loch Laggan to the height of about 4000 feet. From that point we gained a splendid view of the western hills for which we were bound--a white and serrated range extending from the west to