1From Thomas Jefferson to Roberts & Jones, 13 June 1802 (Jefferson Papers)
Having occasion to have a piece of work executed at Monticello which requires the very toughest iron it is possible to find, and some of the best German steel, I will pray you to send me a quarter ton of iron of the toughest quality you can procure, among which let there be 2. bars from 1½ I. to 1⅝ I. square, the rest of smaller bars, some flat, some square; & also 100. ℔. best German...
2From Thomas Jefferson to Thomas Whitney, 13 June 1802 (Jefferson Papers)
I observe in the European catalogues of Optical, Astronomical &c. Instruments, they advertize ‘Artificial horizons by parallel glasses and quicksilver to take double altitudes by, £1–16. sterl.’ I suppose it possible that this may be to supply the want of a good horizon at land and enable us to use Hadley’s quadrant here as well as at sea. should this be the case, and you happen to have one,...