ASTRONOMY. 425 



and ordinary observations of clock stars shows sensible differences in 

 the case of some observeis, who, perhaps, have not settled down to a 

 fixed habit of observing "reversed" stars. For determining absolute 

 personal equations in observations of stars and of limbs of the sun, moon, 

 or planets, a personal equation a})paratus consisting of a vertical plate, 

 with a circular aperture 6 inches in diameter to represent the sun or 

 moon and several small pinholes to represent stars, is placed in the 

 focus of an object-glass of about 7 inches aperture and 50 feet focal length 

 (which is attached to the dew-cap of the transit circle when horizontal 

 and pointing north), and is carried smoothly by clock-work. The times 

 of transit of the artificial objects are observed over the wires of the 

 transit circle, and are also automatically recorded on the chronograph. 



The sun, moon, planets, and fundamental stars have been observed 

 regularly. The annual catalogue for 1884 contains about 1,370 stars. 



The altazimuth has been used in observing the moon from last quarter 

 to first quarter in each lunation. 



For the determination of motions of stars in the line of sight 569 meas- 

 ures have been made of the displacement of the F line in the spectra of 

 47 stars, and 72 measures of the h lines in 14 stars. The observations 

 of the last twelve months confirm the change in the motion of Siriua, 

 which now appears to be approaching the sun at the rate of about 20 

 miles a second. 



Photographs of the sun were taken on one hundred and seventy-three 

 days. On only two days was the sun's disk observed to be free from 

 spots. 



In conclusion, Mr. Christie strongly urges an appropriation for an 

 object-glass of 28 inches aperture and 28 feet focal length, to be placed 

 upon the southeast equatorial mounting, in place of the present object- 

 ive of less than half that aperture. This increased optical power is 

 especially desired for prosecuting the spectroscopic work. 



We understand that the necessary sum has been granted, and that 

 Mr. Grubb is already at work upon the glass. 



Grignon (1884) has made various observations on solar spots, com- 

 ets, meteors, lunar eclipses, spots on Venus and Mars, &c., for which 

 observations, and the conclusions drawn from them, reference must be 

 made to the original report. 



Harrow (Lieutenant-Colonel Tupman's observatory). — The meridian 

 circle has been employed in determining the latitude and longitude of 

 the observatory, and in observing right ascensions of the moon. The 

 approximate latitude found is -|-51o 34' 47", and the approximate longi- 

 tude, from transporting chronometers, I'" 19«'9 west of Greenwich. The 

 equatorial reflector has been chiefly used for observations of comets. 



Harvard College Ohfiervatory. — Professor Pickering's report was pre- 

 sented to the visiting committee December 3, 1885. The death of Mr. 

 Robert Treat Paine has deprived the observatory of the immediate aid 



