524 Progress in Science. (October, 
The value of light railways, especially for thinly populated distriéts, has re- 
cently formed the subje& of a paper, read by Mr. Henry S. Ellis before the 
Exeter Chamber of Commerce. Light railways are of three kinds, namely— 
(1.) Those which follow as nearly as possible the surface of the ground, 
avoiding the hills and the necessities for expensive over or under bridges, and, 
by travelling at low speeds, avoiding the necessity for expensive signal and 
other apparatus usually required by the Board of Trade for through lines. 
The gauge is usually the national one, viz., 4 feet 8} inches. (2.) The patent 
narrow gauge railway, invented by Mr. Fell, which, by being constructed on 
timber supports of different heights, to suit the undulations of the country, 
avoids, to a great extent, severance of land and expensive cuttings and banks. 
The gauge of such lines varies from 8 inches to 2 feet. A railway of this 
description, about a mile inlength, has been recently constructed at Aldershot, 
in 45 days, for the purpose of conveying stores to the Victualling Office. The 
gauge of this line is only 18 inches, but it is capable of conveying siege guns 
7 tons in weight. The cost is about £2000 per mile. (3.) The wire tramway, 
which, like the Fell system, is mounted on iron or timber supports, to suit the 
undulations of the country; but it is only adapted for the conveyance of loads 
not exceeding ro cwts., and is generally employed for short distances only— 
250 yards to 3 or 4 miles. One has been constructed as long as 15 miles. 
Mr. Ellis then gave some very interesting statements regarding a light 
railway recently constructed by the Duke of Buckingham, from which the fol- 
lowing particulars have been taken:—The cost of the Wotton Railway, 
including sidings and two goods’ sheds (one 25 feet by 25 feet, and one 60 feet 
by 25 feet), is rather less than £1400 per mile, exclusive of the value of the 
land. The main line is very nearly 7 miles long. The gradients from 
Quainton to Wotton are favourable,—two short inclines of about I in 
78, in opposite directions, being the worst,—and the general inclination 
being downwards to Wotton, which is 50 feet below Quainton. The gra- 
dients from Wotton to Brill are heavy, the ascent being—with one exception, 
not quite a quarter of a mile—continuous for 23 miles, varying from 
I in 100 to r in 51. The latter is a quarter of a mile; but an incline of 
I in 64, on a curve of 12 chains radius, for a quarter of a mile, is quite equal 
to the steep gradient. The total ascent is about 130 feet in this portion of 
22 miles. The line was q@mmenced on the 8th of September, 1870. The first 
portion to Wotton was in use on the 1st of April, 1871, and the greater 
portion of the remainder was brought into use for minerals, agricultural 
produce, &c., in November: the last quarter of a mile and Brill Station were 
brought into use last April, and another branch of 14 miles in length was in 
course of construction last May. 
Continuous Brakes.—With the extensive development of railway traffic, 
and the extension of train services on existing lines, the necessity for some 
more powerful control over the train, when going at high speeds, makes itself 
more and more felt, especially on heavily worked lines. We have, on more 
than one occasion, recently noticed the different designs which have from 
time to time been put forward, with the view of providing an efficient conti- 
nuous brake throughout the entire train, so that it might be placed under 
more effective control, by enabling it to be suddenly brought to a stand-still, 
and so avoid collision or other accidents which are now too often experienced. 
The best brake of this kind that has hitherto been introduced is that known 
as the Westinghouse Air-brake, which, although only just introduced into 
this country, is already in use on some 20,000 miles of railway in America, 
where it has been applied to 1200 locomotives and 4000 cars. It has already 
been applied in this country to trains on the London and North-Western, the 
Caledonian, and the Charing Cross Railways. Mr. Westinghouse’s invention 
consists of three distinct parts :—First, the arrangements for compressing the 
air; secondly, the appliances by which the air so compressed is conducted 
along the train, and made available for applying the brakes; and thirdly, the 
construction of the signalling apparatus. The latter, however, can only be 
considered as an adjuné to the brake, as it is perfectly complete without it. 
The first part of the apparatus consists of an air-compressing pump, fixed to 
