58° 



[WSCIEM 



[Vol. IV., No. 99. 



seen from the accompanying diagram ; and what is 

 meant by the equation of time, which is nothing 

 more than the difference between mean time and 



DIAGRAM SHOWING COMPARISON OF MEAN (OR CLOCK) 

 TIME WITH SOLAR (OR APPARENT) TIME AT THE 

 SEVERAL SEASONS OF THE YEAR. THE PERPEN- 

 DICULAR CENTRAL LINE REPRESENTS MEAN TIME, 

 AND THE CURVED LINE SOLAR TIME, AT MEAN 



noon. (Borrowed, by permission, from the Popular 

 science monthly.) 



solar time, may be seen by a glance, and is given 

 by the length of a horizontal line running from the 

 vertical line through the zero of the scale, to a 

 point on the curve corresponding to the date for 

 which the equation of time is desired. For all 

 ordinary purposes, the diagram is sufficiently accu- 

 rate; although, of course, it has not all the refine- 

 ments which might be suggested, as, in fact, a 

 single diagram could not be given for all years. 



NEW MAPS OF THE HEAVENS. 



" Nature and Nature's laws lay hid in night. 

 God said, ' Let Newton be ! ' and all was light." 



Pope. 



The accompanying maps represent the heavens 

 from the north pole to 30 south of the equator, 

 and include all stars to the 4^ magnitude inclusive. 

 In some instances those of the 4^ magnitude have 

 been incorporated for the sake of configuration, 

 and convenience of identification. 



The maps also include portions of the milky way, 

 the paths of the planets during the year, with their 

 location in these paths at certain definite intervals. 

 From these the position of any planet for any date 

 can be obtained with sufficient accuracy for finding- 

 purposes. 



The numbers around the circumference of the 

 circular map, and at the top and bottom of the rec- 

 tangular maps, indicate hours of right ascension ; 

 and the other figures along the line of o and 12 

 hours, every ten degrees of declination. The curv- 

 ing line represents the ecliptic or apparent path of 

 the sun in the heavens. 



The months at the borders indicate the part of 

 the heavens that would be on the meridian at nine 

 o'clock in the evening at the various times ex- 

 pressed. Thus, on Jan. 1, the stars along the line 

 of 3.7 hours would be crossing the meridian at nine 

 o'clock in the evening, and on Feb. 1 those on the 

 meridian of 5.8 hours, etc. 



RATES OF DOMESTIC POSTAGE. 



Letters and all other written matter, whether sealed or unsealed,, 

 and all other matter sealed, nailed, sewed, tied, or fastened in any 

 manner, so that it cannot be easily examined, per half-ounce, or frac- 

 tion thereof, 2 cents; postal-cards, each i cent; printed matter 

 (except newspapers and periodicals) , in unsealed wrappers only, each 

 two ounces, or fraction thereof, i cent (limit of weight four pounds, 

 except for a single book, which may weigh more; prepayment com- 

 pulsory) ; newspapers and periodicals, in unsealed wrappers, each 

 four ounces, or fraction thereof, i cent; mailable merchandise, in 

 packages easily opened for examination, per ounce, or fraction thereof, 

 1 cent (limit of weight four pounds; prepayment compulsory) ; regis- 

 tration-fee on letters or other articles, 10 cents. 



I 



