a radius of 11/2 times its diameter or thickness, without fracture; and I proposed a test more resembling the fatigue that a crank shaft has sometimes to stand, and more worthy of this material; and in the event of its standing this successfully, I would pass the material of 30 or 31 tons tensile strength.  Specimens of steel used in the shafts were cut off different parts—­crank pins and main bearings—­(the shafts being built shafts) and roughly planed to 11/2 inches square, and about 12 inches long.  They were laid on the block as shown, and a cast iron block, fitted with a hammer head 1/2 ton weight, let suddenly fall 12 inches, the block striking the bar with a blow of about 4 tons.  The steel bar was then turned upside down, and the blow repeated, reversing the piece every time until fracture was observed, and the bar ultimately broken.  The results were that this steel stood 58 blows before showing signs of fracture, and was only broken after 77 blows.  It is noticeable how many blows it stood after fracture.  A bar of good wrought iron, undressed, of same dimensions, was tried, and broke the first blow.  A bar cut from a piece of iron to form a large chain, afterward forged down and only filed to same dimensions, broke at 25 blows.  I was well satisfied with the results, and considered this material, though possessing a high tensile strength, was in every way suitable for the construction and endurance required in crank shafts.

Sheet No. 1 shows you some particulars of these tests: 

Tensile    Elong.             Fractured    Broke    Fall
Tons.     in 5”     Bend.      Blows.      Blows.     In. 
A =  30.5     28 p. c.    Good       61         78       12

In order to test the comparative value of steel of 243/4 up to 35 tons tensile strength, I had several specimens taken from shafts tested in the manner described, which may be called a fatigue test.  The results are shown on the same sheet: 

B =  241/2                  Good    64    72     7
B     —­        —­         —­     48    54    12
C =  27      25.9 p. c.    Good    76    81    12
D =  29.6    28.4 p. c.    Good    71    78    12
E =  30.5    28.9 p. c.    Good    58    77    12
F =  35.5    20   p. c.    Good    80    91    12

The latter was very tough to break.  Specimen marked A shows one of these pieces of steel.  I show you also fresh broken specimens which will give you a good idea of the beautiful quality of this material.  These specimens were cut out of shafts made of Steel Co. of Scotland’s steel.  I also show you specimens of cold bending: