On Compound Engines for Agricultural Purposes. 661 
XXXVI. — On Compound Engines for Agricultural Purposes. 
Rj Messrs. Easton and ANDERSON, Consulting Engineers to 
the Society. 
The enormous demand which springs up for any type of agri- 
cultural machinery as soon as its advantages are definitely 
proved, leads us to watch the introduction of any new principle 
or invention at the Royal Agricultural Society's Annual Shows 
with the greatest interest, as we know the development and 
improvement of a good germ will be rapid, if it is right in 
principle and suited for meeting a current requirement. 
In 1§41, at the Liverpool Show, the first portable engine was 
exhibited. At Derby this year, 66 portable, 25 traction, 
10 ploughing, and 139 other steam engines of various types 
appeared upon the ground, and the production of portables in 
Lincoln alone must be numbered almost by thousands annually. 
Probably the most potent influences which have developed 
and improved the portable engine have been the public trials of 
them by the Royal Agricultural Society. 
The trials have ceased since the Cardiff Meeting in 1872, as 
the portable engine has been considered to have then arrived at 
such a pitch of excellence, that no material advance can have 
taken place since on the results then obtained. However, there 
is still plenty of room for improvement, and for greater economy 
in fuel and water consumption. The working pressure of steam 
is rising, and would probably rise more rapidly if the Royal 
Agricultural Society gave more encouragement or sanction to 
the use of high pressures ; and evidently many makers are now 
seriously contemplating the adoption of the compound cylinder- 
principle for portable and traction engines. 
At Carlisle last year, Messrs. Garrett showed the first com- 
pound portable engine which has appeared in the Society's 
Shows, though Messrs. Fowler had shown a compact 20-horse- 
power semi-portable compound engine, with cylinders beneath 
the boiler, at Kilburn, in the previous year. 
At the recent Derby Show, Messrs. Garrett, Burrell, Fowler, 
and Aveling and Porter, all exhibited compound engines, which 
received due notice from the miscellaneous Judges and Stewards, 
but could not conveniently be tested this year. 
Messrs. Garrett showed a 10-horse-power portable compound 
engine, with cylinders alongside one another, and cranks at 
right angles, similar in design to the 8-horse-power engine 
shown by them at Carlisle last year, a nice arrangement, which 
will probably be generally adopted, at least in large portable 
engines on the compound principle. They also exhibited an 
8-horse-power portable, with two single-acting cylinders placed 
