364 Intelligence and Miscellanies. 



those of the sphere, namely, the meridians, the equator, the 

 ecliptic, etc., and let us inscribe in their respective places the 

 leading constellations. Let us now cut off the end of the 

 orange next to the south pole, for the space of forty degrees 

 from it, and making the necessary incisions, (as is usual in 

 peeling an orange,) let us double back the respective por- 

 tions of the peel, so as to form them into a circle surrounding 

 the north pole as a centre. The various circles and constel- 

 lations before inscribed, will now occupy their appropriate 

 places on the circle, constituting in fact, a projection of the 

 surface of the sphere, north of 40° south latiude, on a plane 

 parallel to the equator. If we reflect upon the position 

 which each of the inscribed objects would take, we shall 

 perceive that the north pole would occupy the centre ; that 

 the meridians would be projected into straight lines proceed- 

 ing in radii from the centre; that the equator would be pro- 

 jected into a circle, described at the distance of 90 degrees 

 around the pole, and tut by the ecliptic at an angle of 23° 

 28', on each side of which, in a belt of 16 degrees, would lie 

 the constellations of the zodiac ; that the meridians which 

 were fifteen degrees asunder, would constitute true hour cir- 

 cles, and might be numbered accordingly at the extremity of 

 the radii, or the circumference of the circle ; and, finally, 

 that when the circle was turned round on the pole, in its 

 own plane, the sun's place in the ecliptic for the given time, 

 being brought against the hour, (as before numbered) the po- 

 sition of all the various objects represented on the plane 

 would correspond to the actual appearance of the skies at 

 the same moment. 



Such is, in general, the plan on which the stellarota is con- 

 structed, and so far the construction appears to be extremely 

 simple and easy. But a greater difficulty presented itself in 

 devising means to represent the horizon corresponding to 

 any given place, since every diflerent parallel of latitude, 

 would seem to require its own horizon to be represented on 

 the plane of projection. To recur again to the orange, let 

 us see how the horizon of the equator, of the parallel of 46° 

 N. L., and of the pole, would severally arrange themselves, 

 as we double hack the rind into the plane of projection. The 

 horizon of the equator being, or coinciding with, one of the 

 meridians 90 degrees distant, and all the meridians being 

 projected into straight lines, this horizon would of course be 

 a straight line cutting the meridian of the place at right an- 



