However, these new one-piece safes have not discouraged the
malefactors. They have only suggested to them the creation of special
appliances which enable them, without stopping to pick the lock, to
remove from the side wall of the safe a circle of the metal large
enough to allow of an arm to be put inside.
One of the most important of these new devices for assisting the
safe-crackers in their crime is formed of an iron hoop furnished with
well-tempered steel teeth, which is fixed by means of a simple pivot
on the safe after a screw worm has been previously driven in. The
instrument is then turned on its pivot and plows a groove in the safe
wall each time it revolves.
Science has not left the burglar weaponless, however. The progress
accomplished has merely compelled him to obtain higher qualifications,
and in the continuous strife between the armor plate and the desperado
who would pierce it the thieves have had hitherto the last word. For
many years dynamite was their chief reliance, and then a product was
discovered some years ago by a chemist, who gave it the name of
"thermit," by which the cracksman was able to melt sheet metal, inches
thick, with comparatively little trouble.