Unpublished letter, regarding perfect hydrostatics from W Shalders to the Secretary of the Royal Society Shalders writes a letter on a printed copy of an advertisement for a patent for his hydrostatic machine for raising fluids. He asks if the Royal Society believes that it is possible to construct his machine with the desired effect using the parts illustrated on his advertisement. He explains that previous attempts to construct the machine have not been fully successful. John Frederick William Herschel has written his initials next to the date received, and John George Children had written his initials next to the date reading was declined. Subject: Hydrostatics Addressed to the Secretary of the Royal Society at Somerset House, London. Received by the Royal Society on 26 May 1827. Reading declined by the Committee [of Papers] on 31 May 1827. 20 May 1827