The act of assembly of 1785 having, however, restricted the corporation of this Society, not only from selling or transferring, but from leasing, any part of the ground thus granted to them, or of the erections to be made on it, a supplement to that act was obtained, on the 17th of March, in the following year; authorizing the Society to let out any part of their Building, for such purposes as should have an affinity to the design of their institution; but restricting the profits arising from any such lease to the uses for which the Society was originally instituted. The cellars and some of the apartments in the house, have been leased accordingly; and the profits arising from these leases constitute a considerable part of the Society’s funds, which are of very moderate extent. The resident members pay to the Treasurer a small annual assessment, fixed by a by-law of the Society: these payments, in addition to occasional donations in money, made by members and others,[249] form the residue of the funds of the Society; besides which, they receive from time to time valuable presents, in books, astronomical and other instruments, &c. Their library, philosophical apparatus, and collections of various kinds, are now respectable. ----- Footnote 249: It is due to the liberality of the general assembly of 1782-3, to notice in this place, that on the 16th of February, 1783, that legislative body of Pennsylvania made a grant to the American Philosophical Society, of four hundred dollars. ----- The objects of this institution are readily comprehended, from its name; the style of the corporation being—“The American Philosophical Society held at Philadelphia, for promoting Useful Knowledge:” And with this view, in its formation, the fundamental laws (passed on the 3d day of February, 1769,) direct, that “The members of the Society shall be classed into one or more of the following committees: 1. Geography, Mathematics, Natural Philosophy and Astronomy. 2. Medicine and Anatomy. 3. Natural History and Chemistry. 4. Trade and Commerce. 5. Mechanics and Architecture. 6. Husbandry and American Improvements.” The same original laws and regulations of the Society indicate the style of the several officers of the institution, and prescribe the duties of their respective stations: they likewise direct the manner in which the general economy of the Society shall be managed, and their proceedings, in the more appropriate business of their institution, arranged and conducted. “These Rules,” say the Society (in an Advertisement prefixed to the first volume of their Transactions,) “were adopted from the Rules of that illustrious Body, the Royal Society, of London; whose example the American Philosophical Society think it their honour to follow, in their endeavours for enlarging the sphere of knowledge and useful arts.”