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 bv the mirror on the wall. 



pany.) 



•' 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 



739 



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." 



