Thursday, April 26, 2012

Scheiner's Description of the Helioscope

 
Scheiner, Rosa Ursina, Liber II, Cap.XXXIII, p. 133v
 
III
DE TELIOSCOPIO observatorio ordinando, & seligendis, debiteque imponendis lentibus,
 
CAP. XXXIII.
 
   Antequam ad circulum observatorium designandum progrediar, oportet paucis explicare conditiones lentium pro Telioscopio observatorio, & modum easdem debite in tubos collocandi.
   Expono autem hic Telioscopium observatorium ordinarium, quo hactenus usus sum, & utuntur alij, quod non pluribus quam duabus constat lentibus, quarum convexa Solem, concava chartam spectat.
   Quoniam vero in ordine executionis practicae, necessarium est havere lentes, necessarium quoque est easdem in, Telioscopium recte impositas, necessarium illud idem in retinacula debite impositum atque firmatum esse prius, quam uliam operi exercendo manum admoveas; idcirco praeter ea quae hucusque generatim de lentibus differuimus, nunc ad magis particularia Telioscopij descendemus: idque in gratiam Tyronum potius, quam in hisce rebus exercitatorum.
   Telioscopium igitur ob efficaciam atque perfectionem res visibiles in objecta charta distincte repraesentandi ita dictum, consitat partibus materialibus & formalibus. Materiales sunt, tubi, annuli, opercula,formales due lentes, convexa & concava. Tubi Telioscopij possunt esse multi vel pauci, longi vel breves, ampli vel graciles, pro magnitudine atque efficacia lentium. Nam lens ampla, requirit tubum amplum, parva angustum, & spaerae magnae segmentum, longum, &c.
   Materia harum arundinum potest esse vel chartacea, vel lignea, vel metalica: prout animus, vel sumptus cuiusque tulerit. Ita debent esse sibimet subordinati ut minimum & intimum occupet lens cava, convexa maximum, & supremum; omnes ita apposite fabrefacti, ut minoris convexa superficies cylindrica majoris concavam adaequet; sic
 
 
TRANSLATION
 
III
ON THE ORDINARY TELESCOPE observatory arrangement, selection, and proper placement of the lenses,
 
Section 33
 
   Before proceeding to the circle designated the observatory, it is necessary to explain a few conditions on the lenses for the Telescope observatory and the ways they are properly arranged in the tube.
   I will now explain this ordinary Telescope observatory, which I have used so far, the use of the other, in which not more than two lenses appear, in which the convex looks to the Sun and the concave to the paper.
   But since it is necessary to have the lenses in the practical order of execution, it is likewise necessary that the ordinary Telescope be placed on the right, and that the connections be properly arranged, placed and set first before moving to the other tasks at hand; therefore, except for what was generally said about the lenses, we now descend more particularly to the Telescope in favor of the novice rather than those experienced in these matters.
   The Telescope therefore for the effectiveness and the perfection of the thing visible to be distinctly represented on the object card thus, consists of materials and formed parts. The materials are the tube, the rings, the covers, the two shaped lenses convex and concave. The tubes of the Telescope can be many or few, long or short, slender or very wide, according to the size and efficacy of the lens. For a large lens will require a large tube, small a narrow one, and a large round segment a long one, et cetera.
   The material of these reeds can be either paper or wood, or metal, as the will, or the cost will permit. Thus they must be subordinated to those as the small and intimate take the concave lens, the convex the greatest and supreme; all thus suitably fabricated, as the small convex, the superficial cylindrical, and the large concave require; so be it.
 
 
CONCLUSIONS
 
According to the text Scheiner is describing a Galilean telescope projecting an image onto a screen which would be eyepiece projection. (translated with the help of Google Translate)
 

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