104 PROCEEDINGS OP SECTION A. 



to about fifty feet. The tower is provided with a gallery at the 

 top, and a convenient arrangement for fastening apparatus above 

 the central opening in the gallery. The Observatory can be seen 

 from the top of the tower, so that the chronometers can be rated 

 from the drop of the time ball, or from direct astronomical 

 observation, for which purpose instruments will be erected. The 

 main entrance to the Laboratory is below the tower. Partly 

 corresponding to the advanced Laboratories referred to above, but 

 on the opposite side of the corridor, are two small rooms for special 

 purposes. These rooms though small are very perfect in every 

 detail ; the galvanometer shelves having already proved their 

 usefulness. The floors of these rooms are perhaps the most solid 

 in the building, and the aspect being due south, extreme changes 

 of temperature are avoided. 



The Private Laboratory is a large room with windows on one 

 side and at one end. It is built on solid concrete arches and has 

 a large and useful cellar below. There are plenty of slate tables 

 and fittings as already described. One corner is fitted with 

 instrument and bookcases, large office table, etc., etc. There is 

 also a regulation drawing table, and one slate bench is provided 

 with drawers between it and the floor. A door opens from this 

 room into the main Laboratory. This is a room thirty-four feet 

 by forty feet, a portion about ten feet wide being separated from 

 the rest by a thin wall for electric testing and optical work The 

 south side of the main portion is occupied by a long working 

 bench with all the usual fittings. The fire places have both gas 

 and air nozzles. Tliis room like the rest can be made perfectly 

 dark. The usual tables are distributed as close as possible over 

 the floor space. The east side is broken up by a balance case and 

 instrument case and drawers. The north side by shelves, and 

 instrument case and drawers, and a door into the corridor. The 

 dark portion has an optical bench running down its whole length, 

 as well as a slate working table and galvanometer shelf on the 

 east wall. The slate bench is so arranged that it can be lighted 

 by small incandescent lamps {with twisted wires) in various 

 sections. I fear however that some vibration may be found to 

 occur in this wall owing to the machinery in the workshop. If 

 this turns out to be the case the galvanometer shelf will have to 

 be moved to the other wall. The floor of the main Laboratory is 

 very good and firm. 



The Workshop occupies the most easterly position, it is opposite 

 to the Lecture room. A great deal of pains lias been expended 

 to get this department as perfect as possible. The light is very 

 good, both in the day time, and when the gas or electric light is 

 in use. The power is supplied by the engine referred to above. 

 The machines at present set up are : — 



One eight-horse Gas Engine. 



One large ten inch by eight-foot Lathe, sliding and screw cutting. 



