Astronomy in a nutshell, the chief facts and principles explained in popular language for the general reader and for schools . lock and the sun. Thesetimes are April 15, June 14, Sept. 1, andDec. 24. At four other times of the yearthe difference is at a maximum, viz. Feb. 11,sun 14 min. 27 sec. behind clock; May 14,sun 3 min. 49 sec. ahead of clock; July 26,sun 6 min. 16 sec. behind clock; Nov. 2,sun 16 min. 18 sec. ahead of clock. Thesedates and differences vary very slightlyfrom year to year. But, whatever measures of time we mayuse, it is observation of the stars that fur-nishes the means o
Astronomy in a nutshell, the chief facts and principles explained in popular language for the general reader and for schools . lock and the sun. Thesetimes are April 15, June 14, Sept. 1, andDec. 24. At four other times of the yearthe difference is at a maximum, viz. Feb. 11,sun 14 min. 27 sec. behind clock; May 14,sun 3 min. 49 sec. ahead of clock; July 26,sun 6 min. 16 sec. behind clock; Nov. 2,sun 16 min. 18 sec. ahead of clock. Thesedates and differences vary very slightlyfrom year to year. But, whatever measures of time we mayuse, it is observation of the stars that fur-nishes the means of correcting them. 8. Day and Night. The period of twenty-four hours required for one turn of the earthon its axis is called a day, and in astronomicalreckoning it is treated as an undivided whole,the hours being counted uninterruptedlyfrom o to 24; but nature has divided theperiod into two very distinct portions, onecharacterised by the presence and the otherby the absence of the sun. Popularly wespeak of the sunlighted portion as day andof the other as night, and there are no twoassociated phenomena in nature more com-. Morehouses Comet, October 15, 1908 Photographed at the Yerkes Observatory by E. E. Barnard with the ten-inch Bruce telescope. Exposure one hour and a the detached portions which appeared to separate from the headand retreat up the line of the tail at enormous velocity. Morehouses Comet, November 15, 1908 Photographed at the Yerkes Observatory by E. E. Barnard, with the Bruce telescope. Exposure forty minutes. Day and NigKt 97 pletely in contrast one to the other. Thecause of the contrast between day and nightmust have been evident to the earliest humanbeings who were capable of any thought atall. They saw that day inevitably beganwhenever the sun rose above the horizon,and as inevitably ceased whenever it sankbeneath it. In all literatures, imaginativewriters have pictured the despair of primevalman when he first saw the sun disappearand nig
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