Show do artale tired various instances are on record where metals while not showing any appreciable wear have literally fallen to pieces aud that without any assigned canse on one occasion a steel rail after 22 years continuous service on tho great northern railway ial england actually disintegrated under the wheels of a passing train so complete was the breaking up that scientists it worthy of investigation during it was determined that the belal had become exhausted cd and had broken down as au overstrained animal might be expected to do this acs led to further inquiry and scientists aio satisfied that metals do decoulo tired out fine cracks often appear iu steel ras ami it has been supposed that they are caused by the continuous concussion of railway wheels this however leeroe to bo contradicted by tho examination of bewly made rails in which similar fine lines occur the idea hat metals become weary while not altogether a new one is to an extent a plausible one and under the careful scrutiny ecru tiny of scientific will probably bo satisfactorily explained and settled new york ledger |