eers in
charge by lightening their duties and rendering the engines easy to work.

With those advantages it is perhaps not surprising that this valve gear
has been very considerably adopted for many classes of steam engines,
especially where a high result has been required, with economy of space,
and a minimum of complication.

Having crucially tested the original engine on the London and
North-Western Railway, Mr. Webb proceeded to build others similar, and on
his bringing out his Compound Express Engine--notably the most advanced
step in locomotive design of the present day--he adopted this valve gear
throughout. There are now a number of these engines running some of the
fastest trains on the London and North-Western Railway, with the most
satisfactory results.

Following these, others of the leading railways took up the system, and
prominently among these Mr. Worsdell, of the Great Eastern Railway, built
a number of large express engines for his fast and heavy traffic, and is
now building a number of others similar as to the valve gear for his
suburban traffic, which is specially heavy. Also the Lancashire and
Yorkshire and the Midland and others of the chief railways are employing
the system specially for large express engines; the Midland engines having
cylinders of 19 inches diameter by 26 inches stroke, and four coupled
wheels of 7 feet diameter. A number of the above-named engines have run
large mileages, in many cases already exceeding 100,000 miles per engine.
For other countries also a number of locomotive engines have been built or
contracted for--both of inside and outside cylinder types--making a total
of nearly 800 locomotives built and building, many of them being of
special design and large size, up to 20 inches and 21 inches diameter of
cylinder.

In all these the absence of wire-drawing may be specially noted by the
full line at the top of the diagram, showing the admission of steam--this
fullness arising from the rapid and full opening of the port for
admission.

Passing now to the other great type of engines, those covered under the
general designation of marine engines, this gear has been applied to
nearly 40,000 H.P. indicated, built and building, and to all classes and
sizes, from the launch engine with cylinders 8 inches by 9 inches, running
at 600 to 700 revolutions per minute, up to engines for the largest class
of war ships, such as her Britannic Majesty's steel cruiser Amphion, of
5,0