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around 1629 and was the son of
Mathurin Cassegrain and Jehanne Marquet. It is unknown what his education was but he was a priest and professor by 1654. He may have been interested in acoustics, optics and mechanics. At the time of his death he was working as a teacher giving science classes at the
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wrote about the
Cassegrain design and critiqued it harshly, maybe because Huygens felt Newton's design was being "imperilled" by this alternative. Whatever the motives, the storm of controversy that followed had one lasting effect: Cassegrain's name was forgotten.
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In 1997 two French astronomers, André Baranne and Françoise Launay, after a long and meticulous investigation including a search for unpublished manuscripts and the analysis of parish registers in the places where
Cassegrain lived (Chartres first and then
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The identity of this "Cassegrain" has had many theories. His only known publication was the letter on the megaphone/reflecting telescope in the 25 April 1672
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as having found, in 1691, a piece of magnet in the steeple of
Chartres Cathedral, then being repaired after being damaged by inclement weather.
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on the optical axis to bounce the light back through a hole in the primary mirror thus permitting the light to reach an eyepiece.
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The
Cassegrain reflector is a reflecting telescope design that solved the problem of viewing an image without obstructing the
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256:'s buildings between 1684 and 1686, and also in a Paris notarized act from 1693. Another name put forward is Jacques, a
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236:(15th edition, 1974), for example, only goes as far as listing "Cassegrain, N." (this, in turn, seems to come from
413:, Newton's invention appeared a month later, in the Philosophical Transactions of March 25, 1672 (number 81). The
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232:. For a long time, reference works were forced to report his first name as "not conclusively known". The
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on 25 April 1672. In that edition is found an extract from a letter written by M. de Bercé, writing from
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to report the invention, and that letter was published in the
February 29, 1672 issue of the
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Chronicling the Golden Age of
Astronomy A History of Visual Observing from Harriot to Moore
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is named after him, even though his true identity was not known at the time of the naming.
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Note: Based on whether the letters described by M. de Bercé are from
Laurent Cassegrain
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It first appeared in the eighth edition of the 17th-century French science journal
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Réflexions sur la description d'une lunette publiée sous le nom de M. Cassegrain
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with an attached note describing a new type of reflecting telescope, the
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Recueil des mémoires et conférences concernant les arts et les sciences
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Recueil des mémoires et conférences concernant les arts et les sciences
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Recueil des mémoires et conférences concernant les arts et les sciences
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543:, Journal of Optics, 1997, vol. 28, no. 4, pp. 158–172(15)
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Cassegrain: a famous unknown of instrumental astronomy
396:, who promptly published it. Huygens also wrote to
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129:who is notable as the probable inventor of the
476:Stargazer: The Life and Times of the Telescope
145:Laurent Cassegrain was born in the region of
479:. Da Capo Press, Incorporated. p. 131.
327:The Biographical Encyclopedia of Astronomers
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567:17th-century French Roman Catholic priests
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305:List of Roman Catholic scientist-clerics
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162:Connection with the Cassegrain reflector
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504:Chaudon web page on Laurent Cassegrain
373:Chaudon web page on Laurent Cassegrain
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538:André Baranne and Françoise Launay,
577:French scientific instrument makers
266:Mémoires de l’Académie des sciences
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388:reported his first invention, the
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204:who had written a letter on the
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523:(Letter #1892, addressed to
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43:1693 (aged 63–64)
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324:Hockey, Thomas (2009).
234:Encyclopædia Britannica
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435:English, Neil (2018).
250:La grande encyclopédie
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133:, a folded two-mirror
115:[loʁɑ̃kasgʁɛ̃]
532:, vol. 7, pp. 189-191
417:was completed by the
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587:People from Chartres
473:Fred Watson (2006).
210:Cassegrain reflector
172:Cassegrain Reflector
135:reflecting telescope
131:Cassegrain reflector
66:Cassegrain reflector
443:Springer Publishing
423:Jean-Baptiste Denys
415:Journal des Sçavans
406:Journal des sçavans
390:Newtonian telescope
332:Springer Publishing
264:) mentioned in the
218:Newtonian reflector
194:Jean-Baptiste Denys
96:Collège de Chartres
517:Christiaan Huygens
394:Christiaan Huygens
384:In February 1672,
282:Laurent Cassegrain
222:Christiaan Huygens
220:. On 13 June 1672
181:by using a convex
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107:Laurent Cassegrain
20:Laurent Cassegrain
486:978-0-306-81483-9
452:978-3-319-97706-5
341:978-0-387-31022-0
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73:Scientific career
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456:. Retrieved
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386:Isaac Newton
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156:Eure-et-Loir
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93:Institutions
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562:1693 deaths
557:1629 births
506:(in French)
375:(in French)
287:The crater
123: 1629
52:Citizenship
551:Categories
511:References
458:August 24,
347:August 22,
289:Cassegrain
258:chirurgeon
202:Cassegrain
254:Louis XIV
206:megaphone
141:Biography
87:Telescope
299:See also
198:Chartres
147:Chartres
137:design.
33:Chartres
534:, 1888.
411:England
291:on the
276:, near
274:Chaudon
262:surgeon
260:(i.e.,
111:French:
46:Chaudon
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402:French
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83:Optics
79:Fields
56:French
409:. In
311:Notes
246:Paris
152:lycée
481:ISBN
460:2021
447:ISBN
349:2012
336:ISBN
293:Moon
40:Died
29:1629
26:Born
527:),
392:to
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