LOCOMOTIVE ENGINES.

719

bunkers, which hold 2 tons. A powerful screw break is attached tothe engine, actuating six blocks in front of each of the six wheels.Sand boxes supply sand in front of, or behind each wheel, asrequired, and are so contrived as to be opened or closed by one setof levers for each direction of the engine.

The heating surface in this engine is:—

In the tubes, ... ... ... ... ... s... I047’8 sq. feet.

,, fire box, ... ... ... ... ... ... 96*2 ,,

Total,

H44'o sq. feet.

The fire-grate area is nearly 15 square feet.

The weight upon the wheels, when the engine

is in working order

and the tanks full, is:—

Tons. cwts.

On the leading wheels, ...

... 13 16

,, driving wheels, ... ... ... ... . .

... 14 II

,, trailing wheels, ...

... 13 8

Total,

... 41 15

The total wheel base is 15 feet.

The engine will draw a weight of 872 tons on a level at a speedof 20 miles per hour, and a weight of 367 tons up an incline of 1 in80 at a speed of 11 ^ miles per hour, with a working pressure of145 lbs. to the square inch. Its consumption of fuel with this latterload has been 40' 16 lbs. per mile, taking the whole trip, whichincludes the descent as well as the ascent of the gradients beforealluded to. The cost of repairs has not been taken into account,as the distance run does not usually exceed 76 miles per day.

This engine was designed to obtain as much power as was pos-sible upon six wheels. The frames have been put inside the wheels,to allow convenient access to the motive parts; the cylinders beingplaced inside, to secure great structural stability. The tanks arearranged alongside the boiler to distribute equal weights upon thewheels, whether the tanks are full or empty. The distribution ofthe weight, when they are empty, is:—

Tons. cwts. qrs.

On the leading wheels, ... ... ... ... ... n 7 2

,, driving wheels, ... ... ... ... ... u 16 2

,, trailing wheels, ... ... ... ... ... 10 8 2

it is believed that the engine has in all respects answered thepurpose for which it was built.

For engines with rigid frames, a simple and convenient arrange-