Agreeably to your desire I send herewith Garnetts’ Nautical Almanacs for the years 11. & 12—& shall not fail, life remaining, to forward those for succeeding years as soon as published.

I have lately added to the common artificial horizon, (the polished plane surface adjusted by a spirit-level) a very simple appendage, by the aid of which any altitude of the sun &c may be taken, on land, from 0 to 90°, either by the common octant or sextant, with the utmost ease & accuracy—a desideratum, so far as I know, hitherto unattained, in the use of this valuable instrument.

Instead of giving you a description of this apparatus, I request you will permit me to send you one, with directions for its use. It is no larger than a moderate sized snuff-box. By what conveyance can I forward it?—