Most of the small tools mentioned in article 9th of Report of December last, have been procured. Some are still wanting; but these are few. No Aberthaw lime has been procured, nor any pozzolano. Mr Stevenson intends to send the Yacht for a cargo of Aberthaw limestone, as soon as she can be spared from the service of the Light-houses; and, if a vessel is purchased for the accommodation of the workmen at the Rock, she may also be sent for a cargo of Aberthaw lime. I have not been able to procure any pozzolano, although many trials have been made. I have some hopes that a small quantity may still be procured; but I cannot speak with certainty: if not, tarras, or burnt ironstone, must be used. No oak trenails for the stones have yet been got. Mr Stevenson, however, is about to order some from Southampton; and I hope they will be in time for the work. Lead is, at this time, very cheap. I submit it to the wisdom of the Commissioners, whether it might not be advisable to purchase now what may be wanted for the work.
As to the construction of the Light-house, I submitted a plan to your consideration in the month of February last, (see [Plate VII.]) According to this plan, the works are proceeding; plans of each course of stone have been made; the whole is dove-tailed, but somewhat different from the mode pursued at the Edystone; they are less in length on the outside, but deeper in the direction of the radius of the Light-house, which will render the structure, on the whole, stronger than the Edystone plan. The extension of the base of the building is also much greater; and the base is considerably different. By this means, not only the impulse of the waves on the building will be less, but their action on the part of the rock adjoining the foundation will be much easier. The Rock is softer than that on which the Edystone is built, but it is harder than I imagined when last here. On the whole, I feel confident, that this work will be brought to a successful termination, within a reasonable period. The knowledge which has been acquired by the operations of the last season, impresses me with additional confidence in the practicability of the work, although confident, from the commencement, that, with proper care and attention, such a work might, with certainty, be completed.
The necessity of Mr Stevenson’s remaining much at the Rock while the operations are going forward, render it necessary that some person, by way of agent, should be appointed to pay money at Arbroath, and to credit and settle accounts. As to this the Commissioners will order as they think right. I am, honourable gentlemen, your most obedient servant,
(Signed) JOHN RENNIE.
To the Honourable the Commissioners of the Northern Light-houses.
REPORT by Mr RENNIE.
Edinburgh, 12th December 1808.
Gentlemen,
I visited the Bell Rock on the 25th ult. The weather was favourable, but the tide did not ebb so low as to allow me to examine the foundation of the masonry so completely as I could have wished; but as there was little swell, I was enabled to form a tolerable judgment concerning the perfection with which it is executed, and this, I have the pleasure to say, is very favourable.