No. 55 497. 



Cosmology. 



661 



55 495. 1 = 9. 



55 496. 1 : 8. 



55497. 1:6. 



55,491. Apparatus for Demonstrating Equinoctial Precession 



55,492. Horizon after Bath, Fig are 



This apparatus permits of explaining the terms: "Plane, Horizon, Dead Level, East, West, North 

 and South Points, East-West Line, North-South Line, Diurnal Circle, Diurnal and Nocturnal Arc, Point 

 of Sunrise and Sunset, Eastern and Western Amplitude, Point of Culmination, Equator, Tropics, Sun's 

 Altitude on the meridian and Altitude of the Pole", and answers the questions: When and how far 

 does the sun set or rise from the Eastern and Western points? How large is the diurnal or nocturnal 

 arc? At what altitude is the Sun (angle of the horizontal surface)? What is the inclination of the 

 horizontal surface to the earth's axis (polar altitude)? 



These questions can be put for any part of the Northern Hemisphere and for any day of the year. 



55,493. Apparatus for Explaining Ebb and Flow, after Archenhold, Figure 



A large white sphere represents the solid interior of the earth which is supposed to be com- 

 pletely surrounded by water. The aqueous masses are represented by a white wire frame and a small 

 sphere, representing the moon, is connected with springs to the earth's core. If the lunar sphere is 

 taken away from the earth the aqueous masses (as in the case of ebb and flow) are changed from 

 the spherical shape, and the tidal wave is shewn on the side turned towards and away from the 

 moon: this tidal wave being smaller on the side turned away from the moon, corresponding to the 

 greater distance from the latter. The earth can be rotated thus rendering the change from ebb and 

 flow every six hours plainly visible. The action of the solar flow, amounting to about 2 / 6 ths of the 

 lunar flow, can be represented for the case of new and full moon by drawing away the lunar sphere 

 to a greater extent, and for the case of the first and last quarters by drawing it away to a lesser 

 extent. 



55,495. Celestial Globe after Haller, Figure, with movable socket, adjusted for one degree 



of latitude . 4. 0. 



When ordering it should be stated for which degree of latitude the apparatus is intended. 



The globe can be set for any month, day or hour. The invisible part of the heavens is con- 

 cealed by the socket. The apparatus is applicable for shewing the stars of the firmament visible at 

 any time and also for solving a few astronomical problems, e. g., determining the rising and setting 

 and the highest position of the stars. 



55,496. --idem, Figure, with fixed socket and movable globe; can be set for any degree 

 of latitude 



By arranging the globe to be movable the apparatus, in addition to being used for the purposes 

 mentioned, can also be employed for demonstrating the apparent rotation of the heavens during 

 twenty-four hours by observing the same from any position on the earth. 



55,497. Uranotrope after Dr. Wislicenus, Figure 



s. d. 

 1.16.0 



4. 16. 



4. 4.0 



The Uranotrope serves for demonstrating the apparent rotation of the heavens and the apparent 

 motions of the stars. It is formed essentially of a hollow brass sphere of about 20 cm diameter capable 

 of rotation about an axis passing through it, in the centre of which axis placed a small terrestrial 

 globe. This glass sphere represents the apparent terrestrial sphere, the terrestrial equator, the ecliptic, 

 the tropic and polar circle, also the coloures of the equinoxes and solstices being etched on and painted 

 in different colours Other entries should be made by the students during instruction by means of a 

 coloured pencil supplied, with ink, or by pasting small paper pieces on the globe; the paper can be 

 removed by washing off. Complete description and instructions for use are appended to the ap- 

 paratus. 



01. 5313 1 , 6228, 3811. 



7. 10. 



2. 4.0 



