ASTRONOMY. 197 



each instrument from each pair of stars (Safiord's catalogue), is given 

 in detail, and compared with the results of past years. 



The mean of all tbe observations for latitude made in 1884, is as lol- 

 lows all- pairs and observations having equal weight: 



Zenith telescope by Wurdemanu (190 observations on 43 pairs) gives 



40O 47' 20".47. . ^ . ,,._ 



Zenith telescope, by Lingke (333 observations on 54 pairs) gives 40 



47' 20".92. . ... 



Grand mean for observations of 1884, giving observations and instru- 

 ments equal weight, is 40° 47' 20".75. 



The results of previous years are added for comparison (1 =101 



feet :) 



Transferred from old observatory 40o 47' 21''.70 .-t 0';.575 



In 1880 (320 observations of 84 pairs) -l^^-^^ ± " -"^ - 



1881 (5'Jl observations of 104 pairs) ^^'//o 



• 1882 (235 observntions of GO pairs) '^^','^1 



1883 (497 observations of 118 pairs) '^^'I'l^^ 



1884 (523 observations of 89 pairs) 20". i o 



" The grand mean of 2,172 observations made at the new observatory 

 during the past five years is 40o 47' 21".23; but it will be noticed that 

 tbere has been a steady reduction in the yearly means during this en- 

 tire period, and that the less exact determination at the old observatory 

 indicates a change in the same direction." „ , w. .^nino 



Althoun-h the nature of the observations and the small absolute ^ a ue 

 of the quantity in question render it quite possible to attribute this 

 solely to errors of observation, the fact is, nevertheless an ex remely 

 interesting one in its relation to the question of the variability of terres- 

 trial latitudes, and deserves furth-er ex-mination. 



Longitude was determined by lunar culminations, and the errors ot 

 each separate result compared with the known (telegraphic) longitude 

 were: 7«.5: 36.0; 2.2; 15.1; 3.8; 10.4; 14.G; 5.5. 



Lonc^itudes by lunar distances were also determined with errors as 

 below ^1G^5; 12.9; 7.3; G.7 ; 4G.4; 39.7; 23 9; 11.7. 



Auroral displays are regularly noted by the sentinels, and an inter- 

 esting table of the results since 1870 is given. „w^„^ 



What has been given as an abstract of one year's work m only one 

 department of this school of application for young engineer oflicersi^ 

 sufficient to show that we have at present no better school of practical 



astronomy in America. r^^Hooa i« now 



Yale College Observatory.-The observatory m Yale ^oHege is no^ 

 without a director, Trofessor Kewton having resigned that office last 

 M yr^eing now the secretary to tbe board of managers, -^ose presi^ 

 dent is Di Porter, the president of the college. The points of most 

 ?mpo an e n the secretary's report for the year 1S84 relate to he pho- 

 To!Z^oi the late transit of Venus taken by Mr. Willson, and now in 



