POPULAR ASTRONOMY. 



289 



though of this we cannot be certain. 



The "man in the street" has been rath- 

 er disappointed with the comet because 

 is has not blazed forth brightly long be- 

 fore this. The reason is not hard to 

 find. At the first return since the "pre- 

 diction was made by an Englishman," 

 in 1759, the comet was discovered 78 

 days before it passed the sun, in 1835, 

 a period of 102 days elapsed before dis- 

 covery and perihelion passage. By long 



Halley's is not the only comet now 

 visible. On December 6, Mr. Zaccheus 

 Daniel, at Princeton, found the fourth 

 comet of the year 1909, with a five and 

 three-quarter inch telescope, and it is 

 consequently visible in a small instru- 

 ment.. Though Mr. Daniel is but thirty 

 years old, he has discovered three comets. 

 The new Daniel comet, which is in the 

 constellation of Auriga, is moving north- 

 wards and has no tail. 



Evening SkyMap for January 



Jan. Moon phases 



LastQYr. Jan. 3. 

 Me.wMoon.Jan. II. 

 First Q'tr..J an is. 

 FullMoonJan.25. 





FACESOUTHAND 

 HOLD THE MAP OVER 

 YOUR HEAD -THE TOP 

 NORTH, AND YOU WILLSEE 

 THE STARS AND PLANETS 

 JUST AS THEY APPEAR 

 IN THE HEAVENS 



SOUTH 



exposures with a sensitive photographic 

 plate, Max Wolf found Halley's comet 

 on September 11, no less than 220 days 

 before perihelion passage. If the same 

 number of days only were to elapse as 

 in 1835, on January 1, 1910, Halley's 

 comet would be still undiscovered. We 

 must possess our souls with a little pa- 

 tience, for the comet will not disappoint 

 us. During January the comet will move 

 from the constellation of Aries into Pis- 

 ces, and at the end of the month will set 

 about 9 P. M. 



THE PLANET MARS. 



Though Mars has now passed her 

 greatest brilliancy and is getting farther 

 away, the interest in it has not abated. 

 The question of the constitution of the 

 atmosphere of the ruddy planet is most 

 important. All astronomers are agreed 

 that there is very little water on Mars, 

 and this scarcity of water makes it nec- 

 essary to postulate irrigating canals in 

 order to carry the water from the polar 

 Caps so that life may be maintained. 

 Moreover, all are agreed that the tern- 



