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Link: • Michael Christopher Hanov to Carl Linnaeus, 15 April 1768 n.s.
Dated d. 15 april. 1768.. Sent from Gdansk (Poland) to Uppsala (Sweden). Written in Latin.


Michael Christopher HanovHanov, Michael Christopher
(1695-1773). German. Professor of
philosophy and librarian, Danzig.
Correspondent of Linnaeus.
encloses a Programma with his letter to Linnaeus. He seizes the opportunity to thank Linnaeus for the letter he received about two years ago [this letter has not come down to us]. In his previous letter Hanov mentioned unknown fishes provided with osseous stings which are used as handles by countrymen. He refers this species to Pastinaca, the same genus as rays, Rajae; to Linnaeus it is perhaps a Platessa or a Limanda. The fruit he described belongs to the family of Palmae nuciferae. Hanov believes that monkeys have a sensitive but irrational mind and differ from human beings by having four hands. Hanov has treated this in Physica III and IV, which has now been published [[Hanov refers to the philosophy formulated by Christian WolffWolff, Christian (1679-1754).
German. Philosopher, professor of
mathematics in Halle in 1707, deposed
from his office in 1723 because of his
philosophical opinions, reinstated in
1740 as professor of mathematics,
natural law and the law of nations.
, on which he himself had published Philosophiae naturalis sive physicae dogmaticae tomus [I-IV] ; Tanqvam continuationem systematis philosophici Christiani L.B. de WolffHanov, Michael Christopher &
Christian Wolff
naturalis sive Physicae dogmaticae tomus
I[-IV] ; Tanqvam Continuationem
systematis philosophici Christiani L.B.
de Wolff
]. Later he has elaborated the first section of “Ars inveniendi” concerning the faculty of the invention of things that are certain or almost certain, to be achieved empirically through observations and experiments, in search of the qualities and quantities of things, but also through rational scrutiny a priori. As these special problems are offered rewards, this one seems to be worth a higher reward: it is not only an improvisation but a comprehensive system. He still keeps it as a manuscript; even if he cannot be a candidate of a prize, he can at least expect a contribution to the publication. He is now in the second part which applies the invention of verisimilitudes to rules. A third of this is now completed. Among other novelties he has come into contact with there is a means of optimizing human vision so, without optic aid, it becomes so perfect that it surpasses even the best microscopes. There is a method of navigating at sea without the guidance of the stars, or the “horologium harrisonianum” [the “Harrisonian clock”, Hanov refers to to the marine chronometer, invented by John HarrisonHarrison, John (1693-1776).
British. Carpenter and later a
clockmaker, inventor of the marine
chronometer, an instrument for solving
the problem of establishing the
East-West position or longitude of a
ship at sea.
] there is a principle for navigation inherent in the ships, according to the wind and their hulls, at calm weather or headwind etc. Hanov is now 72 and has little hope of achieving more. He will die in the hope of having inspired others to complete what he has not finished.

P.S. Hanov hopes that the observers of the passage of Venus under the sun will concentrate on examining the doubts of P. Hellus [Hanov refers to Maximilian HellHell, Maximilian (1720-1792).
Hungarian. Astronomer and an ordained
Jesuit priest, director of the
observatorium in Vienna in 1756. Upon
the invitation of the King of Denmark he
went to the north of Norway in 1769 to
observe the transit of Venus before the
sun. The Royal Danish Academy of
Sciences and Letters funded the
publication of his 1770 account of the
Venus passage.

class="Uline">Source: F.
Szenkovits, "Hell Miksa (Maximilian
Hell,1720–1792 )", Technical
Review, Historia Scientiarum 2 30
(2005) 13–26 (summary in English); art.
in Wikipedia based on Alexander
Moutchnik, Forschung und Lehre in der
zweiten Hälfte des 18.
Jahrhunderts: Der Naturwissenschaftler
und Universitätsprofessor Christian
Mayer SJ (1719-1783)
], a Viennese astronomer, who recently claimed that the form of Venus in the telescope was due to a satellite of Venus [Hell’s observations were published in his Observatio Transitus Veneris Ante Discum Solis Die 3. Junii Anno 1769Hell, Maximilian Observatio
Transitus Veneris Ante Discum Solis Die
3. Junii Anno 1769. Wardoëhusii,
[...] Facta, et Societati Regiae
Scientiarum Hafniensi praelecta

(Copenhagen, 1770).
, funded by the Royal Danish Academy of Sciences and Letters, Det Kongelige Danske Videnskabernes SelskabKongelige Danske Videnskabernes
Selskab, Royal Danish Academy of
Sciences and Letters
Danish. The
Academy was founded in 1742. It
establishes its name as
Kiøbenhavske Selskab af Laerdoms
og Videnskabers Elskere (Copenhagen
Society of Lovers of Learning and
Science) from at least 1745 to perhaps
as late as 1770. In 1777 it became
Kongelige Videnskabers Selskab, and by
1781, it had become the Kongelige Danske
Videnskabernes Selskab (Royal Danish
Academy of Sciences and Letters). Its
publications are Skrifter som udi det
Kiøbenhavnske Selskab af Laerdoms
og Videnskabers Elskere ere fremlagte og
, 1-10 (1743/1744-1765/1769
[i.e. pub. 1745-1770]) and Skrifter
som udi det Kongelige Videnskabers
Selskab ere fremlagde og nu til trykken
, 11-12 (1777-1779).


a. original holograph (LS, VI, 260-261). [1] [2] [3]