During the remainder of the month of April and the commencement of May we had frequent stiff gales; and it often happened that the men could not venture out of the Barrack, owing to the heavy sea which swept over the Rock. The crane, too, which had been erected at the wharf for unloading the stones, although its top stood about 8 feet above the Rock, was often buried in the breakers and seemed in hourly danger of being carried away, an event which we were the more ready to fear from our experience in a former season, when the crane disappeared during a heavy westerly gale. The sea on those occasions also broke so heavily on the Barrack, that the windows of my apartment, which were about 55 feet above the sea, were often darkened by the sheet of water which flowed over them after the house had been struck by a wave. From those causes it was not till the 18th May that we were enabled to occupy the Rock in full force; and on the day following we commenced building the 38th course on the top of the last year’s work.
After that period we had a long continuance of north-easterly winds, which always brought both smooth water for landing materials and dry weather for building; so that by the 23d of May our work had made such progress and the Tower had risen so high, that the chain of the balance-crane, which had been raised along with the building, by sliding it upwards on the cast-iron pillar or shaft placed in the centre of the Tower, could not reach the top of the shear-poles, by which the stones were raised to the level of about 40 feet above the Rock; and it was found necessary to rig from the lowest window a beam or needle (in the manner described at [page 155], and as also shewn in Plate IX. of my Father’s Account of the Bell-Rock Lighthouse), as an intermediate stage between the top of the Tower and the shear-poles on the Rock. The needle, as already noticed, projected horizontally from the window and the stones were raised by a chain which passed over the sheave at its outer end and was wrought by means of a crab placed in the interior of the Tower. In that manner we continued for about six weeks, with little interruption from the weather, to raise the blocks of stone to the top of the Tower by successive needles from storey to storey; while the mortar, lewis-bats and other lighter materials were raised at once by means of a line wrought by a windlass placed on the Rock.
On the night of Saturday the 9th of July, however, a heavy sea, caused by a combination of high tides and strong gales, threw down some of the stones of the belt course which lay piled up round the base of the Tower ready to be raised for building; and they were with great difficulty, but most happily, saved from the insatiable deep. The loss of any of the stones of that course would have been a serious obstacle to the progress of the works and might have prevented our completing the erection of the lantern until next year; and indeed, as that course formed a prominent feature of the Tower, any slight injury even to the arris or corners of the outer face would have been much to be regretted. It was with great satisfaction, therefore, that it was found on examination next morning that none of the stones had sustained the slightest damage.
Last Stone. On the 21st July the last stones of the Tower were safely landed on the Rock, under a salute from the steamer, as an expression, no doubt, of the satisfaction which the commander Mr Kerr and his crew naturally felt at having successfully brought out not fewer than 75 lighter loads, or about 1500 tons, of stone during the season, as well as in some measure of their joy at the prospect of a speedy and happy termination of our arduous labours. The process of landing, indeed, owing to the fine weather that prevailed throughout the season, was very easy, compared with that of former years; in proof of which, I may state, that in 1841, there were often as many as five warps broken at a single landing, while in 1842, not a single rope was broken in the discharging of the stones. On the 25th July the last stone of the parapet or top-course was built; and immediately thereafter we proceeded to remove from the Tower, the balance-crane and the cast-iron pillar on which it was swung, and to make way for the erection of the Lantern.
In looking back upon the works we found great cause for thankfulness for the successful conclusion of the building operations, without loss of life, or even the occurrence of any serious accident, excepting the destruction of the first Barrack in November 1839. It also gave me great satisfaction to reflect that, however difficult a rigid adherence to scrupulous accuracy of workmanship may be in such a situation as the Skerryvore, it had nevertheless, from the exactness with which the stones were dressed, on no occasion been necessary, throughout the execution of the whole work, to deviate from the rule which I had laid down of carefully gauging the diameter of each course and of admitting no variation from the true form materially exceeding ¹⁄₈ inch. Every part of the stone work, indeed, was fitted in an accurate manner and the floor stones, in particular, which serve as ties across the building, were finely dressed and carefully set. All opportunities were also embraced, whenever it was practicable, to grout each course over night that the recent masonry might be in a state fit for building upon in the morning; and by those precautions and the peculiar properties of the mortar used, any disadvantages from very rapid building were entirely avoided. Even the elliptic cavetto which forms the cornice and which projects no less than three feet from the face of the wall, although bearing a very heavy entablature or plinth, never gave any signs of settling outwards; and when I examined it from a stage hung from the end of the balance-crane just before it was removed, there was no appearance of any change in the thickness of the joints, although the outer heads of the stones had been purposely kept a little high to allow for any tendency to settlement. The effect of the cornice is very bold and striking and is quite in accordance with the simple and almost severe style of the pillar itself. The masonry of the Tower is 137 feet 11 inches in height and it contains 58,580 cubic feet or about 4308 tons.
The day after landing the last stone of the parapet, the steamer started from Tyree for Greenock, with two lighters in tow, for the transport of The Lantern. the Lantern; and by the 10th of August the whole was landed on the Rock. No time was lost in preparing the beds for the sole-plates of the Lantern, and that operation had been nearly completed when my Father, in the course of his annual tour of inspection, as Engineer for the Northern Lights, visited the Rock, two days after the iron work had been landed. By the 16th the whole of the sashes and the frame of the roof were to their places; and on the same day the fixtures of the lightning-conductor were completed. On the 18th of August Mr Bruce, the Sheriff of Argyll, and some gentlemen who accompanied him and had spent the preceding night at Hynish, visited the Rock; and, after breakfasting at the base of the Tower, ascended to the top and minutely inspected every part of the work. They afterwards returned to Hynish, whither I accompanied them and had an opportunity of pointing out to Mr Bruce the various works in progress there. The party sailed for Oban in the afternoon of the same day.
From want of room on the Rock it was found necessary to build the roof of the Lantern in separate pieces instead of rivetting together the sheets of which it was composed on the ground, and raising the whole to the top in one mass, as is usually done; but, in spite of that disadvantage, the work was brought to a close for the season on the 14th September, on which day the glazing of the Lantern was completed and the glass was covered with a framework of timber to protect it from the sea-fowls which frequent in myriads the Rock and the Tower. The workmen were, on the same day, removed from the Rock, although with much difficulty, owing to the heavy surf which broke over the landing-place and rendered the embarkation more perilous than almost any I had before experienced at the Skerryvore.
CHAPTER IX.
CONCLUDING OPERATIONS AND EXHIBITION OF THE LIGHT.
The shores of Tyree, as already often noticed in these pages, and as deplored by Martin 140 years ago, in his Account of the Hebrides, afford few places of safety fit even for boats. It had therefore been determined, by the Commissioners, that any attempt at Harbour Works. the construction of a harbour should be strictly confined to the provision of a place of shelter for the vessel which was to attend the Lighthouse. Much attention had been bestowed on the subject, not merely by myself during my five years’ acquaintance with Tyree, but also by Mr Thomas Stevenson, who succeeded me in the charge of the works at Hynish, at the time when I was appointed Engineer to the Lighthouse Board in January 1843, after the completion of the masonry of the Tower. A small sandy beach at Hynish, which lies embayed between rugged rocks, had been selected as the fittest place for the pier; and all the materials had been landed and shipped there, so that we naturally looked to it as the site for the projected harbour, not only as presenting works already finished, which might be made available as part of a more extended plan, but as a place which, during an experience of some years, had justified our anticipations as to its being less frequently disturbed during stormy weather than most of the neighbouring creeks. All that was contemplated in the proposed plan, was to form a small basin in which the vessel could lie sheltered in all states of the weather, and from which she could find an easy departure in any condition of the sea which would permit a landing to be made on the Rock. The Skerryvore Steamer having been sold and a small vessel of 35 tons, named the “Francis,” having been purchased at Deal, the dock accommodation at Hynish was, for the sake of economy, laid out with reference to the shelter of that vessel. It was calculated that a basin 100 feet in length and 50 feet wide, would afford sufficient room for such a vessel; and as her draught of water is between 7 and 8 feet, it was thought sufficient to provide for a depth of about 12 feet at high water of spring-tides, which, it was expected, would render the dock accessible during good springs at about three quarters flood.
The exposure of the shore at Hynish, to the effects of heavy westerly swells, made it desirable to avoid carrying the entrance of the basin so far seaward, as, under more favourable circumstances, would undoubtedly have been done; and it was accordingly determined that the landing pier should be extended to about 40 feet seaward of low-water mark, and terminated in a round head, as shewn in [Plate X.], having a talus wall on its seaward face, composed of rough blocks, arranged in courses regularly receding, so as to form a slope of 45° of inclination, as shewn in [Plate XI.] The inner face of that pier, being nearly vertical and guarded by fenders of timber, had served as the quay for landing and shipping stones and other stores and it now forms one side of the basin or dock. The other side consists of a shorter talus wall, built about 60 feet to the westward of the first, and, together with the crossheads projecting from each wall and containing the gateway, completes the inclosure of the basin. In the gateway, booms are employed, as the shifting nature of the sand and the heavy seas render gates inadmissible. The space contained between those walls was left completely dry at low water of spring-tides, and was chiefly composed of rock, covered with a thin layer of shifting sand, which varied in depth with the state of the wind and sea. The rocky matter, consisting of decomposed gneiss, was excavated to the extent of about 5000 tons, in three separate compartments, protected by successive dams of rubble masonry, built with Pozzolano mortar, and presenting an aggregate area of 7339 square feet. Those dams, two feet thick, proved so water-tight, that by the aid of a small hand-pump, the excavation and the building of the entrance heads of the booms went regularly forward without any delay, although the men worked in the bottom of the pit, surrounded on all sides by the sea, which, at high water of spring-tides, rose 17 feet above them. The dams were sheltered from the action of the swell by a temporary breakwater of heavy blocks, which formed a convenient roadway for the transport of the materials during the progress of the works, and which were removed at the close of the operations.