several scientific voyages to Madagascar and the East Indies. His
Voyages à Madagascar et aux Indes Orientales was originally published in 1791 and reprinted with the same title in 1793 and 1802. In this edition of 1807 the portion
relating to Madagascar was omitted and the title changed accordingly.
Jefferson was acquainted with the Abbé Rochon, and frequently mentioned him and his discoveries in correspondence with his
scientific friends. In a letter to David Rittenhouse dated from Paris, January 25, 1786, he wrote: “
. . . in a letter to m(
~
r)
Hopkinson I mentioned to him that the Abbé Rochon, who discovered the double refracting power in some of the natural chrystals,
had lately made a telescope with the metal called Platina, which while it is susceptible of as perfect a polish as the metal
heretofore used for the specula of telescopes, is inattackable by rust as gold & silver are . . .
”
Writing to Benjamin Franklin two days later, on January 27, Jefferson mentioned: “
. . . not a sheet I think has come out since your departure which is worth notice. I do not know whether before that the Abbé
Rochon had thought of using the metal Platina for the specula of telescopes. indeed I believe the thought is not his originally,
but has been carried into execution before by the Spaniards. it is thought to take as high a polish as the metallic composition
generally used, and is not liable to rust . . .
”
Almost twenty-seven years later, on December 27, 1812, in a letter to Robert Patterson, Jefferson wrote: “
. . . I recieved at the same time the Abbé Rochon’s pamplets
[
sic
]
& book on his application of the double refraction of the Iceland Spath to the measure of small angles. I was intimate with
him in France, and had recieved there, in many conversations, explanations of what is contained in these sheets. I possess
too one of his lunettes, which he had given to Doctor Franklin and which came to me thro’ m
(
~
r)
Hopkinson. you are therefore probably acquainted with it . . .”
In the Jefferson Papers in the Library of Congress is a page in Jefferson’s handwriting headed:
For engraving in the Abbé Rochon’s method.
[3805]
27
Deux voiages faits en Allemagne par Cassini.
1815 Catalogue, page 115, no. 33, as above, but spelling
Voyages and
4to added.
CASSINI DE THURY,
César François.
Relation des deux voyages faits en Allemagne par ordre du Roi par rapport à la figure de la terre, pour déterminer la grandeur
des degrés de longitude; par rapport à la géographie, pour poser les fondemens d’une carte générale et particulière de l’Allemagne;
par rapport à l’astronomie, pour connaître la position des principales villes où les astronomes allemands ont fait leurs observations
. . . par M. de Cassini de Thury.
Paris:
Durand,
1763.
First Edition. 4to. 94 leaves, plates; no copy was seen for collation.
Quérard II, 71.
Lalande, page 483.
Entered in Jefferson’s undated manuscript catalogue with price,
5.17.
César François Cassini de Thury, 1714-1784, French geographer and astronomer, was a member of the famous Italian family of astronomers. He was born at the
Observatory in Paris, and in 1771 the post of director of that institution was created for him.
[3806]
28
Clarke’s Seaman’s desiderata by Garnett.
4
to.
1815 Catalogue, page 115, no. 14, as above,
4to p.
CLARKE,
Henry.
Clarke’s Seaman’s Desiderata: or, concise, practical rules for computing the apparent time at sea, the latitude from double solar
altitudes, and the longitude from the lunar observations. With a simple and expeditious method of clearing
