TH. JEFFERSON.

CITY OF PHILADELPHIA, February 23, 1792.

I do hereby certify that the foregoing Letters-patent were delivered to

me in pursuance of the Act intitled an Act to promote the progress of

useful arts: that I have examined the same, and find them conformable to

the said Act.

Scientific American Supplement, No. 492, June 6, 1885 · 第 15 / 59 题