ASTRONOMY. 281 



time. The zone 100-5°, lately undertaken, will not be finished before 

 1885. 



Albany : Zone 5°-l°. Some GOO observations are yet to be made, 

 17,000 having been made. 



JSfikolaief : Zone -|-lo-2o. No reports were received. 



AVe learn from a recent letter of Prof. O. Stone, director of the Mc- 

 Cormick Observatory, that his Burclimusterung (or zone observation of 

 all the stars from the iirst to the tenth magnitude inclusive), from —23° 

 southwards, is progressing rapidly. The zones are 1° wide, and four 

 zones are nearly finished, so that printing may commence this year. 

 Schoeufeld's DurcJirmtsternng (from — 2o to — 23°) is also nearly ready 

 for publication. 



Definitive positions of the red stars. — Part IV. of the Astronomical 

 Observations and Researches made at Dunsin]c,the Observatory of Trinity 

 College, Dublin, contains the mean places of 321 red stars, deduced 

 from observations made with the meridian circle at Dunsink by Dr. 

 J. L. E. Dreyer. 



The work contains about 1,140 observations of the 321 stars, each of 

 which has been observed on the average three and a half times. Of 

 these observations, 445 were made by Dr. Copeland in 1875-'76, and 

 the remainder by Dr. Dreyer in 1878-'80. 



The epoch of the catalogue is 1875.0, and the system is that of the 

 Astron. Gesell. zones, so that subsequent comparisons will be easy. 

 The work begins with an account of the Pistor & Martins meridian 

 circle. Its aperture is 6.38 inches, focus 8 feet. The power used has 

 been 180. This circle is similar in design to those of Ann Arbor, Al- 

 bany, Copenhagen, Leyden, Washington, and Leipsic. The standard 

 clock by Dent is mounted in the observing room. The observations 

 have been made by eye and ear over wires only 3".2 apart, and Dr. 

 Dreyer says, what is tolerably clear, that this interval is too small. 



The pointing in declination is done by means of two threads 14 inches 

 apart. 



There is a difference in the size of the (exactly cylindric) pivots equal 

 to — Oi'^MO. The collimation has been determined over mercury. The 

 equator-point has been determined from the zero stars of the Astron. 

 Gesell. The latitude is not definitively determined, but is taken at 53^ 

 23' 13".0. 



There is a difference in the horizontal flexures of the instrument, 

 CI. E. and CI. W., but the absolute flexure is small. Both circles are 

 finely divided, and the division errors of each are given. The eight 

 micrometer screws have been twice investigated. The constants of the 

 instrument have been investigated by all the various methods, and the 

 results by the various ways agree well. 



Dr. Dreyer would confer a favor if he would describe in detail his 

 plan for getting the exact position for the counterpoise weights referred 

 to on page 7 of his work. It would be interesting to know how much 



