Signature:
Francûs de Bailloû S.C.R. Ap. Maiestatis Opticus Mediolani 1761”
Signature Notes:
Inscriptions:
No stand present.
Collection:
Louwman Collection of Historic Telescopes
Accession #:
LC 73
Sources:
Project investigation
Louwman, P.J.K., and Zuidervaart, H.J., "A Certain Instrument to See Far: Four Centuries of Styling the Telescope Illustrated by a Selection of Treasures from the Louwman Collection of Historic Telescopes". Wassenaar, 2009. p.89-90. #78.
Louwman, P.J.K., and Zuidervaart, H.J., "A Certain Instrument for Seeing Far: Four Centuries of Styling the Telescope Illustrated by a Selection of Treasures from the Louwman Collection of Historic Telescopes". Wassenaar, 2013. p.93. #73.
Public Notes:
"Main tube made of wood, covered with black sharkskin, bordered by two brass edges. Six drawtubes covered with brown marbled paper with gold tooling. Lens fittings made of boxwood with fine screw thread. Signed on the brass edge around the objective: ‘Francûs de Bailloû S.C.R. Ap. Maiestatis Opticus Mediolani 1761’ [meaning: ‘Franciscus de Baillou, Optician of Her Royal and Imperial Majesty in Milan’]. Length 49-120 cm, Ø 7 cm.
At one side of the diaphragm (Ø 1.5 cm) of the two-lens objective is written in French: Objectif microscopique; et pour les object éloignes dans des journées sombres en racourcissant la lunette. (‘Microscopic objective, for distant objects during dark days and to shorten the telescope’).
At the other side is written in a concentric way: L’ouverture du milieu de ce couverle, en y òtant le petit bouchon, elle sert retrecir l’ouverture de l’Objectif Microscopique, / pour avoir de cette façon une excellente lunette d’approche, pour regarder toute sorte d’objects dans des / belles journées, en laissant la lunette dans toutes ses autres parties belle, qu’elle a servir pour / éclaircir des objects dans des journées sombres, et dans des lieux obscurs. (‘Open the middle of this piece and remove the small cap, then one reduces the opening of the lens for objects close by . In this way one obtains an excellent telescope for observing any kind of objects during nice days, and one keeps the other parts of the telescope neat until they are needed during dark days and on dark places’).
On the eyepiece is written: On enforcera ce tuyau jusqu’à cette marque et quand / on voudra observés les asters avec le petit tuyau /garni des deux verres oculares astronomiques. (‘One shifts the tube up to the mark if one wants to observe the stars with the small tube with the two astronomical eyepieces’)" (Louwman and Zuidervaart, 2013).
Dioptrice is made possible by the generous
support of the National Science Foundation, the National
Endowment for the Humanities, the Program in the History and
Philosophy of Science at the University of Notre Dame, and the Adler Planetarium & Astronomy Museum.
