Philadelphia Decr. 25th. 1815
I would hereby take the liberty of introducing to your notice the bearer of this, Mr. Hassler, who has recently returned from Europe, with the apparatus of instruments, which, in execution of his mission for that purpose, he had there procured for the Government of the United States.
A description list of these instruments (which are at present in my custody) has lately been transmitted to the Secretary of the Treasury. It contains two complete sets of all the instruments necessary for the survey of the coast, or for the running of boundary lines, with the utmost accuracy; as also, for two permanent astronomical observatories.
Mr. Hassler is a gentleman of very rare accomplishments. He is not only perfectly acquainted with the construction & use of all the instruments, & the necessary mathematical calculations connected therewith; but could, with his own hands & tools, make most of the repairs or additions that might be wanted.
I would therefore, Sir, take the further liberty, most respectfully to solicit for him such temporary or permanent employment as you may judge expedient, believing, most confidently, that he would be found to discharge the duties required in any employment connected with the use of the above instruments, with reputation to himself, & honour to his appointment.
There are several parts of the apparatus, especially those for the measurement of base lines, which were purposely brought from Europe in somewhat of an unfinished state, but which Mr. Hassler himself, with the aid of a carpenter to make a few wooden stands, can complete as well as could have been done in Europe, & at much less expense. His time, therefore, during the winter, might be very profitably employed in this business.
Relying on your goodness to excuse the freedom I have thus taken, I am, Sir, with the greatest respect & esteem Your most obed. servt.
DLC: Papers of James Madison.