TRANSACTIONS OF SECTION G. 959 
The paper concluded with the expression of a hope that a thoroughly practical 
cell for traction purposes may be introduced—one which will stand rough usage 
’ and be free from the defects which characterise those at present in use, 
TUESDAY, SEPTEMBER 9. 
The following Papers were read :— 
1. On the Form of Submarine Cables for Long-distance Telephony. 
By W. H. Preece, F.B.S. 
The early possibility of talking by telephone between London and Paris has 
directed the author's attention to the proper form of cable to give the best result. 
There is a particular size of cable for every circuit, which will give the smallest 
possible outer diameter of gutta-percha at the least cost to secure clear speech. 
For the new Channel cable this comes out: weight of copper 160 lbs. and weight 
of gutta-percha 300 Ibs. per nautical mile. The paper contains the mathematical 
development that leads to this conclusion. 
2. Column-Printing Telegraph. By ¥. Hicarss. 
This apparatus was originally patented ten years ago, and is now being practi- 
cally introduced for the transmission of intelligence in this country. 
The receiver, which is entirely automatic, consists of a type-wheel and frame , 
carrying the paper-sheet. The former derives the motive power for its rotation 
_ from a train of wheelwork and a weight, and the latter from the battery at the 
sending end. 
The type-wheel is displaced laterally, after each print, by means of a screw, and 
upon completion of a line of printing is released and returned to zero by a spring 
which has been wound up by the movement of the printing-lever. 
One train of clockwork is employed, and the motive power for printing, feeding 
the paper, and traversing the type-wheel, is supplied by the printing electro- 
magnets. 
About twenty of these instruments may be introduced into the circuit of a single 
line of wire, and any number may be worked from one transmitter, The type 
rotates at any desired speed (from 100 to 150 revolutions per minute),and the same 
signals operate both the type rotation and the printing, the difference being that 
the signals for printing are longer than those operating the escapement, in order to 
afford time for the establishment of the full strength of the current in the circuit, 
and to overcome the inertia of the comparatively heavy parts of the printing 
mechanism. 
The other operations of synchronising, spacing between lines, &c., are deter- 
mined by the angular displacement of the type-axis with respect to its zero position. 
The transmitter is driven by an electro-motor, the speed of which is kept 
uniform by an electrical governor. 
A counter upon the transmitter announces to the operator when a line of type 
has been filled. 
From 1,800 to 2,000 words per hour would be the maximum speed. 
Five thousand words can be received without attention, and the paper-supply is 
sufficient for the reception of 30,000 words. 
3. On Heavy Lathes. By A. Greenwoop. 
