Lacock Abbey, Chippenham
July 14. 1836
My Dear Sir
If you attend the meeting of the British Assocn at Bristol, <1> may we have the pleasure of seeing you at Lacock either before the meeting, or after it, as may be most convenient; any day after 14th August we shall be at home.
an early answer will oblige.
Believe me
Yours most Truly
H. F. Talbot
I have a contrivance for registering the heighth of the tide, which I think would answer very well on trial. It consists in admitting the water thro’ a pipe of some length into a reservoir (to insure tranquility of surface in the latter) and placing vertically in it a board covered with white paper on which a chemical composition has been washed, which turns yellow on contact with water. This will of course mark the highest point to which the water rises, and you are secured from negligence of the attendant, because the register may be read off any time before the next high water – I have found on trial that this paper is not discoloured by the action of a moist atmosphere, but requires the actual contact of water, & when dry again, it does not lose the yellow colour it had acquired, in any degree. Therefore I think it would answer the end proposed –Notes:
1. Before the 1836 Bristol meeting of the Association for the Advancement of Science, beginning 22 August, WHFT invited Sir Charles Wheatstone (1802–1875), scientist, Sir William Snow Harris (1791–1867), scientist, Sir David Brewster (1781–1868), Scottish scientist & journalist, Prof Charles Babbage (1792–1871), mathematician & inventor, and Dr Peter Mark Roget (1779–1869), scientific writer to Lacock Abbey. [See Doc. No: 03339, Doc. No: 03352, Doc. No: 03338 and Doc. No: 03341].