C. A. Steinheil S5hne, Miinchen. 115 



sun glass and also with ocular prism of 27 millimeter (12'") aperture 

 fitted in rotating mount which may be fixed in any position, for ob- 

 serving stars in the vicinity of the zenith. 



Shortened Tube with Objective System of 81 millimeter 

 (36'") aperture and 125 centimeter (46") equivalent focus. The tube 

 has a length of only 540 millimeter and is mounted upon a similar 

 stand to that of the preceeding telescope. 



The terrestrial magnification is 58, the astronomical magnifica- 

 tions are 46, 92, 138, 184 and 230. 



Ocular fitted with sun glass; finder of 20 millimeter (9"') aper- 

 ture and 16 centimeter (6") focus: magnification 6 X- 



Telescope with one elbow, 



without stand, with brass tube and ocular movement; micrometer ocu- 

 lar; objective' centering head. 



A rectangular prism with silvered hypotenuse surface, in center- 

 ing mount, is placed between the objective and ocular. 



The errors introduced by the prism are compensated by the 

 construction of the objective. The images are thus rendered perfectly 

 correct, (vid. Vierteljahresschrift der Astronomischen Gesellschaft, Leipzig, 1883, 

 18. Jahrgang, p. 255, paper by Dr. Ad. Steinheil on ,,the theory of 

 telescopes." 



Transit prismfor taking time and polar altitudes, (vid. Kunst-u. 

 Geiverbeblatt fuer Bayern, Munic. 1885, pp. 4 13 and Astronomische Nach- 

 richten. No. 569). 



Parts: Telescope of 7 millimeter (3'") aperture and 54 milli- 

 meter (2") focus; the astronomical ocular magnifies 8 times; sun glass; 

 correction in azimuth and altitude. Fitted in small handy case. 



Pocket Heliotrope 



for signalling at great distances, (vid. Schumacher's Jahrbuch 1844, Stutt- 

 gart and Tubingen, Cotta). 



The instrument consists of a horizontal perfectly plane mirror 

 of 43 millimeter (19'") length and 27 millimeter (12"') width, the 

 silver coating of which has been removed at the center so as to leave a 

 transparent area of 3.4 millimeter (1.5'") diameter. 



While sighting through this aperture an orientation image may 

 be seen of the sun which by means of the movable mirror may be 

 directed to any desired point. All points covered by this orientation 

 image are illuminated by the heliotrope. It can be recognized at a 

 distance of 50 kilometers. This instrument replaces the telescopic 

 heliotrope. 



Goniometer, 



for determining refractive and dispersive powers of various media and 

 for measuring the angles of prisms. Mounted upon cast iron stand 

 fitted with levelling screws. This supports a conical hollow steel 

 center which has an alhidada attached to it. A brass spindle which 

 may be rotated by hand and also by means of a micrometer screw 



