of the Fuigstaff Observatory. 99 



fcctly steady manner. From this room a communication is 

 established with a platform on the roof, to enable the ob- 

 server to descend with the least possible delay from the roof 

 down to the stand for the electrometer. 



Part of the same room is devoted to the photographic ap- 

 paratus, and part to a small mechanical workshop, intended 

 for keeping the instruments constantly in repair. 



I have now accomplished the task I proposed in describing 

 the buildings of the Observatory, and in connection with 

 them it remains only for me to explain my reasons for scat- 

 tering them over the whole ground, instead of uniting them 

 in one compact whole. 



The explanation is simply this ; I had to make use of the 

 buildings of the late signal station, as I found them, in the 

 best possible way, and the circumstances referred to in the 

 beginning of this paper did not admit of my free disposal of 

 the ground, and I was compelled to select certain portions 

 for the building of the magnetic department. The plan of 

 arrangement ultimately adopted being in no way injurious to 

 the magnetic observations, I felt no hesitation in following it. 



Before leaving the exclusively descriptive part of this paper 

 I have still to enumerate the different instruments which are 

 in use in the observatory. They are as follows : — 



In the Horary House — 



Differential Declinatorium. 



„ Inclinatorium. 



„ Apparatus for h. intensity. 



(According to Lamont's construction, and executed in the workshops of 

 the Royal Observatory in Munich. ) 



In the Absolute House — 

 A Magnetic Theodolite, with all appurtenances for determin- 

 ing the three magnetic elements, apparatus for deflec- 

 tions and oscillations, and differential inclinatorium. 

 (As above. ) 

 A Dipping Circle, with four needles and apparatus for invert- 

 ing the poles. 



(From the atelier of Inspector Meyerstein, in Gottingen.) 

 In the Circular Brick Tower — 

 A Universal Instrument. 



(From the Mechanical Institute of Ertel and Son, in Munich. ) 



In the Transit House — 

 A Transit Instrument from Potter, London. 

 ' h2 



