Baltimore
& Ohio 4-4-0 Compound Locomotive
This American-type
engine is now running on the Baltimore & Ohio Railroad, having
been in both freight and passenger service since it left the shops. The
builders have experimented with the engine continually, with the idea
to develop and improve the engine as far as possible. They state that
they are now in position to go ahead and make comparisons between this
compound and the ordinary locomotive of the same class on the same
road. The economy in actual practice, while not exactly actual, so far,
has been so apparent that in these tests which are to be undertaken,
the company expect that a saving of at least 25 per cent, of fuel will
be made.

(from an 1890 magazine, in the public
domain)