100 PROCEEDINGS OF SECTION A. 



First the gas — an inch pipe on each side furnished with little 

 swivel arms bent twice, so that they can either come up and lie 

 flat on the table when connected to Bunsens, or fold quite out of 

 the way and tuck in neatly below the slate when out of use. 

 There is good reason to be pleased with this arrangement and I 

 am surprised never to have heard of, or seen it before. Usually 

 there are distributors on the table ; and these are invariably just 

 where you wish to stand the last piece of apparatus ; or the india- 

 rubber tube has either to be bent round, or passed through a hole 

 in the table top — an arrangement inconvenient in itself, and often 

 leading to annoyance by causing the rubber pipe to flatten and 

 cut oft' the gas. I give a sketch of my arrangement and can 

 tlioroughly recommend it. Besides this there is a water-pipe 

 with taps at appropriate intervals but only on one side of the 

 table — viz. that turned towards the audience. The nozzles are about 

 three inches long and vary in diameter from | at the points to about 

 |- inch at the upper end. These nozzles are adopted throughout 

 the building ; they are of course corrugated and one has a chance 

 of making india-rubber tubes really tight on them. There is also 

 a steam pipe (from a tubular boiler in the workshop) running 

 along below the lecture table in a box packed with slag wool. 

 Tliis steam pipe runs throughout the building being well packed 

 everywhere, provided with expansion joints, aud arrangements for 

 letting oft" condensed water. There is an electric supply laid on 

 from the storage cell house by means of two cables of 19 number 

 16 wires each. This is tapped by large binding screws at intervals 

 along the facing board, and by an arrangement in the cell house 

 can be supplied with as big a current as it will carry. All 

 binding screws are well insulated from the woodwork with asbestos, 

 the screws passing through carefully dried boxwood sleeves. The 

 positive and negative terminals are distributed in such a way 

 that one sort is always at least a foot from the other in order 

 to lessen the danger of short circuiting. To make all safe the 

 circuit is interrupted by a large plug switch in a locked box near 

 tlie door. A current from sixty of the largest storage cells, capable 

 of being coupled up almost anyhow, is not a thing to play with. 

 Tlie lectui^e table is also provided with a pipe carrying an air 

 blast from a Root's blower in the workshop. This terminates in 

 an inch nozzle. I intend to set up a vacuum apparatus such as is 

 used by the Vacuum Brake Company in connection with the steam 

 service ; meanwhile the water velocity pumps do fairly well. I 

 have also arrangements ready for bringing in a belt from the 

 shafting in the workshop, but so far a small electromotor works 

 so well that I have not I'eqviired it. The ventilation is partly 

 provided for by holes (with gratings) through the walls, partly by 

 the holes opening into the corridor, partly by the windows being 

 of two sashes over-lapj^ing with six inches between, and partly by 

 the chimney and fireplace. In order to avoid having to deal 



