Providence, March 3, 1791. “Enclosed are my Weekly Return of Cash No. 30, and Monthly Schedule of Bonds for Feby.… I have also just received your Letter of the 18th. of December last,1 together with the Hydrometer, intended as a substitute to Dycas’s, the Directions for their use.… Particular attention shall be paid to your Directions relative to this Instrument.…”