28 ANNUAL OF SCIENTIFIC DISCOVERY. 



and had sold to the company, taking a share of the savings effected 

 as the pecuniary consideration. The defence set up was singular 

 enough. The complainant asserted, and as he believed, proved that 

 the saving in fuel amounted to over 30 per cent ; and he demanded a 

 verdict in accordance with his statement. The defendants, however, 

 called Mr. Benjamin Isherwood, the Chief Engineer of the U. S. 

 Navy, to prove not only that the particular cut-off which afforded the 

 casus belli could not possibly effect the alleged saving ; but that the 

 only possible saving which could be effected by that, or any other 

 cut-off, amounted at the maximum to 18 per cent, and that therefore 

 a saving of 30 per cent was a physical impossibility. This statement 

 is startling enough ; but Chief Engineer Isherwood does his work 

 thoroughly, and he proceeded to strengthen his evidence by swear- 

 ing that no one believed his ' new discovery ' to be true until i860, 

 and that since then, ail the new marine engines for the navy were 

 built and building upon it. It is nothing new to us to learn that 

 American engines generally are constructed without much regard to 

 the strict principles which can alone secure economy. The indicat- 

 or and its use are almost unknown in the States. This little instru- 

 ment affords the only known means of ascertaining the exact duty 

 performed by steam within a cylinder ; and in its absence we can only 

 form a vague idea of the really useful effect produced by the combus- 

 tion of fuel. A constant habit of observation and a thorough practi- 

 cal acquaintance with a large number of steam engines of different 

 constructions, working under varying conditions, can alone give that 

 knowledge, which will permit us to build engines capable of doing a 

 large duty with little coal. This knowledge is tolerably well dif- 

 fused throughout the workshops of Great Britain ; the young engi- 

 neer being generally afforded every opportunity for testing the act- 

 ual performance of engines by the aid of the indicator. More can 

 be learned in this way in half an hour, than can be derived from the- 

 oretical instruction, however good, in a year ; and we cannot expect 

 men who are almost, or altogether unacquainted with tlfe nature and 

 properties of the instrument, to turn out first-class engines. It is 

 very probable that we shall be accused of attaching an undue impor- 

 tance to so small a thing. Those who have studied the subject will 

 take a different view of the matter, and will, without doubt, indorse 

 a statement which will bear repetition, namely, that without the use 

 of the indicator there can be no real knowledge of what does or 

 does not constitute a good engine. Until its use extends in Ameri- 

 ca, we do not look for much improvement in steam engineering. Al- 

 though our Western friends are somewhat lax in their practice else- 

 where, we did not expect that their navy would afford such prece- 

 dents as Mr. Isherwood's evidence indicates ; evidence, too, which 

 comes upon us with all the force which can be conferred by an oath, 

 and all the strength which can be derived from the high position of 

 the swearer. Mr. Isherwood has, we fear, led many a feeble mind 

 astray. The engineers of Washington possess a great deal of com- 

 mon sense; however, Mr. Mat I ingly's friends sent to New York for 

 Mr. Dickinson, an ailept in engineering, and a man learned in the 

 law as well, a combination of professional attainments all too rare 

 in England. Mr. Dickinson's powers of cross-examination threw 



