104 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



edition of the " British Catalogue ; " which work has also 

 been followed in the omission of all letters except those 

 which are found in Bayer's maps. All the positions have 

 been brought up to 1850. 



The figures of the constellations are printed from different 

 plates and in a distinct color from that of the more import- 

 ant parts. 



Price, on high mahogany frames, the pair, $78.00. 

 " " " " " and com- 



passes, the pair, - $85.00. 



Thirteen-inch Globes. The artificial globe is a round body 

 or sphere, having on its surface a map of the earth, or of 

 the celestial constellations, as delineated, with the principal 

 circles of the sphere. In the former case it is called the 

 terrestrial in the latter, the celestial globe. (See Figs. 116, 

 opposite page.) Artificial globes are used for the purpose of 

 conveying to young persons the first ideas of the figure and 

 rotation of the earth, of latitude and longitude, and the 

 situation of places with respect to each other, and to the 

 sun at the different seasons of the year. It is usual to 

 employ them also for the purpose of solving mechanically a 

 few elementary problems of astronomy, relative to the dif- 

 ference of the hour of the day at different places ; the 

 times of the rising and setting of the sun ; the limits of the 

 visibility of eclipses, etc. 



The fundamental parts of these instruments which are 

 common to both, are, first, the two poles whereon the 

 globe is supported, representing those of the world; second, 

 the brazen meridian, which is divided into degrees, and 

 passes through the poles ; third, the wooden horizon, 

 whose upper side represents the real horizon, and is divided 

 into several circles ; fourth, a brass quadrant of altitude ; 

 fifth, two hour circles, one moving round each pole as a 

 centre, and divided into twice twelve hours, to indicate 

 those of the day and night. The best globes have also a 

 magnetic compass attached to the frame. Upon the surface 

 of the globes are depicted the lines of latitude and longi- 

 tude, the equator, ecliptic, tropics, and polar circles. On 

 one globe, in addition to these, are the various countries, 

 seas, etc., of the world ; and on the other, the stars in their 

 relative positions. 



