Page:Popular Science Monthly Volume 89.djvu/753

This page needs to be proofread.

Popular Hciencr Manllih/

��Watching Dishonest Employees with the Aid of Mirrors

A NOVEL fraiid-flotcrlor invented 1)\- Henry iMullcr.ol Philadelphia, Va., enal)les tlic proprietor of a business, sealed at his desk in another room en- tirely separated from the rocjni in which his customers arc being ser\ed, not only to observe the actions of hi- ■■•'-)!..•(•.- but to have be- fore him at all times an ac- curate repro- duction of the operation of the cash register.

If a dishon- est employee fails to ring uj) the proper amount on the cash register, the proprietor in his room above can in- stantly detect the fraud. In brief, the in- vention calls for a cash reg- ister with spe- cial indicators which project upward, a mir- ror in a clock or other en- closure on the wall near the cash register, and a tube run- iMng through the floor to the proprietor's desk, upon which i.s a glass through which the reflections of the mirror on the wail of the room below are visible.

The tube arranged in the i)o:^ition shown in the accompanying illustration would not excite the suspicion of em- ployees. The indicators which mo\e U])- ward when the keys on the casii register

.rc depressed to show the amount pur-

liiascd are a part of the drawer. Each indicator is providcfl with a numi)er. If ten cents is deposited the numeral ten ino\es upward to a certain angle and is reflected by the mirror on the wall.


•' new

���The proprietor, watching trie glass on the desk before him, discovers that an employee is not ringing up the correct amount on the cash register


The Inventor of the Steam Engine Was Interested in Gim- Cracks

W.\ TT was interested in a quantity r)f inventions and devices," writes 1'". W. Taussig, Prolessor of Economics in Harvard I 'ni\ersit\-. ("Inventors and Money-Maker^," The Macmillan Com- "Among liiem may be mentioned kiii'l ol (lock which, to quote Watt's own language 'is to be ranked in mechanics as riddle.-, and re- busscs are ranked in poe- try.' Other "gim -cracks" were a microm- eter ; a draw- ing machine; a copying ma- chine for let- ters, prototype of the copy- ing devices now so long in use: a ma- chine for dry- ing linen anil muslin by steam ; one for gelling illum- inating gas from coal; a new kind of oil lamp long manufactured at the Soho Works; and a s Ml oke-con - suming de\'ice, on the down- draft principle. Last, but not least significant, was a machine for copy- ing (reproflucing) sculpturt-. which he himself termed a 'hoLb\ -horse,' and which seems to have amused and indee<l absorlted him for ihe last twenty years of liis life (from I7<)I to iSio). Long after he was prosperous and honored, the old man spent much timr in his garret, hot or cold, over this machine; he was sure il wf»uld succeed. He spoke of it as the 'diminishing madiine.' The gar- ret in which he worked at it was long preserved by his descendants."

�� �