38 ANNUAL OF SCIENTIFIC DISCOVERY. 



state of trial, consist in a development of our faculties, and in the power of 

 comprehending those laws and provisions of Nature with which our finite 

 reason does not enable us at present to become cognizant? 



REQUISITES FOE IMPROVEMENT IN MECHANICAL CONSTRUCTIONS. 



What we want is iron of great strength, free from seams, flaws, and hard 

 places. Inferior iron (with the use of other defective and improper materials) 

 is, perhaps, the mam cause of one of the greatest errors committed hi the con- 

 struction of whatever in mechanism has to be kept in motion. I mean the 

 increase of size of the parts of a machine or carriage, hi order to get strength, 

 thereby adding weight until they are considered to be strong enough. In our 

 vehicles of draught and carriages this is strikingly the case. Now, this ought 

 not to be. Lightness is the thing to ami at, and safety should be sought in 

 the elasticity, form, and good quality of the material. Should a carriage be 

 found to twist and get out of form, that would be a proof of its being too 

 light. But to prevent a carriage breaking down by increasing the size of 

 its parts, and thereby adding weight, is mechanically wrong. Indeed, it is 

 quite distressing to see the enormous weight of our carriages, particularly 

 those drawn by animal power. It should be an axiom in mechanics, that what- 

 ever has motion should be as light as circumstances will admit, and this 

 applies equally, whatever the source of power may be, whether the motion is 

 produced by human, horse, or steam power. I think no estimate can be 

 fonned of our national loss from the over-multiplication of sizes. Take, for 

 instance, the various sizes of steam-engines stationary, marine, and locomo- 

 tive. In the case of marine-engines, the number of sizes up to 100 horse- 

 power will probably not be short of thirty, where ten perhaps would be 

 ample. If so, look at the sums expended hi patterns, designs, and hi the 

 number of tools for their manufacture. Nor is this all ; for, if there were only 

 ten sizes instead of thirty, there would be three times the number made of 

 each pattern ; and, as you know, the very soul of manufacture is repetition. 

 Mr. WhitivortJi's Address before the Institution of Mechanical Engineers, Glasgow. 







BERDAN'S COMPRESSIBLE LIFE-BOAT. 



A committee appointed by the Secretary of the Navy, several months since, 

 to test and report on the different life-boats offered to the public, has com- 

 pleted its experiments and made its report to the Department ; the boat which 

 received the commendation of the committee was one invented by Mr. H. 

 Berdan, of New York City. A large number of boats were tested by the 

 Committee, and its report describes them at length ; but we simply copy a 

 portion concerning the one to which they gave their preference, viz. Berdan's: 



" This boat comes nearer the object required in our instructions than any 

 boat presented. She is of a very ingenious construction, and may prove valu- 

 able in the mercantile marine from her compactness and buoyant properties. 

 Her buoyancy may be judged by the following test to which she was sub- 

 jected in smooth water: Fifteen men were placed in the boat offered for 

 inspection (being twelve feet long) and two sixty-four pound weights sus- 



