THE DOMINION ASTKONOMICAL OBSERVATOKY. 



The work carried on at and in connection with the observatory dur- 

 ing the past year may be conveniently described under the following 

 heads : — 



Meridian Work and Time Service; 



Astrophysics ; 



Geophysics ; 



Miscellaneous ; 



Surveys. 



Meridian Work and Time Service. 



Meridian Circle — The new Meridian Circle, which arrived about the 

 end of last October, was mounted in the early part of the winter, as soon 

 as some necessary alterations had been made in the piers. The observa- 

 tions made with it have not been very numerous, and were obtained 

 under considerable difficulties, owing to the fact that the Transit House 

 is not yet altogether completed. It was found that the vertical circles 

 had been slightly damaged in shipment, and they were accordingly re- 

 turned to the makers to be re-turned and re-graduated. Later it 

 developed that the piers on which the instrument was mounted were un- 

 stable, owing to the action of the frost; this will unfortunately necessi- 

 tate their complete reconstruction. 



It is proposed to erect piers for azimuth marks, north and south 

 of the Meridian Circle. The primary marks will be fixed underground 

 for stability, while on the piers will be movable marks, which can be 

 set vertically over the underground ones by a process similar to that 

 used at the Royal Observatory, Cape of Good Hope. This, it is hoped, 

 will furnish marks whose absolute stability can be relied on for consider- 

 able intervals, if not permanently. The coUimating lenses for these 

 marks, situated within the building, will also be movable, for adjustment 

 over similar marks. 



An observing couch has been designed, and the order has been placed 

 for its constmction. It will run on the same rails as the reversing car- 

 riage, and will comprise mechanism for quick setting in any desired 

 position, combined with a slow motion for the final adjustment. 



Work on the opening mechanism for the roof shutters, and altera- 

 tions in the vertical wall shutters, is now in progress, and it is hoped to 

 have the reconstruction of the piers pushed to completion as soon as 

 possible. It is likely, however, that it will be some months before the 

 instrument can be got into actual service. 



