PHYSICAL LABORATORY AT THE UNIVERSITY OP SYDNEY. 103 



batteries for use in the Laljoi-atory. Tlie cells themselves are 

 charged by a rather small Edisoii-type Dynamo, made by my 

 brother and myself some years ago — and driven by our eight-horse 

 Otto gas engine. It is probable that this Dynamo will be supple- 

 mented by another as it is hardly large enough for emergency 

 requirements. A rather complicated switch-board is supplied in 

 connection with the cells, Dynamo, and supply and liglit circuits. 

 This board was designed by Mr. Pollock. Arrangements are made 

 for coupling the cells up in almost any desired fashion by bolting 

 and soldering tlie ends together with copper lugs between them. 

 Voltmeters and ammeters are provided at convenient places on 

 the switch-boards. There are also ten large cells for use locally ; 

 these can be charged by means of the supply — without being- 

 moved — in whatever part of the building they may happen to be. 



LABORATORIES. 



Going down the corridor, the next room to the Library is the 

 Chemical Laboratory. Besides being fitted up with all the fittings 

 described for the other rooms it has a large stink cupboard ; a very 

 perfect chemical working bench : a large gas holder from which 

 the Laboratory oxygen supply is drawn ; and generally speaking- 

 all the fittings usual in a Chemical Laboratory. In this as in the 

 other rooms several gas pipes are passed below the floor, and 

 standards and disti'ibutors provided so as to allow of a table with 

 gas supplies being set up almost wherever required. The wooden 

 tables of which large numbers are set up throughout the Labora- 

 tory ai'e from a design furnished by the Cambridge Scientific 

 Instrument Company, and have already shewn that they are just 

 the right height and length and bi'eadth. The dimensions are — 

 height to top three feet two inches ; length of top, five feet ; 

 breadth of top, three feet. The tops of these cedar tables are 

 grooved on the under surface and strapped to the frame work just 

 like drawing boards ; this seems to have kept them flat so far. 

 Each table has a groove round the upper edge to catch mercury 

 in. Immediately beyond the Chemical Laboratory lie two 

 advanced Laboratories, each of the same size and furnished with 

 everything. The floor of one of these rooms is especially strong 

 and good. These rooms measure twenty feet by ten feet. 



The small rooms round the base of the tower are devoted to 

 lavatory purposes. Beneath the floor of the tower is a room 

 about twelve feet by twelve feet which has no communication 

 with the external air except through a trap door, being for the 

 most part underground. Access is obtained to this place by 

 means of the trap-door and a ladder. It is intended as a constant 

 temperature chamber. The trap-door being in the centre of the 

 horizontal section of the tower — the extra fifteen feet of depth 

 may be utilised for such experiments as the tower is designed to 

 facilitate, seeing that it brings up the etiective height of this last 



