From James Short: Bill and Receipt, with Notes on the Care of the
Telescope
DS and AD: Historical Society of Pennsylvania
1762 July 28th
Dr. Franklin Dr. to James Short
| To three new Speculums to a 2 foot reflecting |
| Telescope and reparations of the Brass work &c; |
London 2d Aug. 1762 Received of Dr. Franklin the above Sum in
full of all Demands
[On the reverse side:]
Endorsed: Mr Short £10. 10. 0
Rules given by Mr. Short to keep the Telescope in Order 1. Let the
Speculums never be touch’d, or wip’d. 2. When the Tube in observing
is left for any time open, let it be in a horizontal Position, that
Dust may not settle either on the great or small Speculums, which
would on one or the other, if the Tube be either elevated or
depress’d. It is the Dust does the Mischief as it attracts the
Moisture and both corrode.