Popular Science Monthly 



267 



Coaxing Music from 

 a Pile of Rocks 



AMR. FROST, of Mar- 

 blehead, Mass., was en- 

 gaged in clearing his land 

 of some huge, flat rocks, 

 when he accidentally struck 

 one with his hammer. It 

 emitted a clear musical note. 

 He struck another in the 

 same way. The tone given 

 out was equally clear and 

 sweet but different in pitch. 

 Trials with other stones of 

 different shapes and sizes 

 convinced him that it was 

 possible to arrange the stones 

 so as to get the notes of the 

 scale. 



After various experiments 

 he piled the stones as shown 

 in the accompanying photo- 

 graph, securing thus a primi- 

 tive instrument that any cave-man might 

 have envied. 



Household Bookless Bookkeeping 

 on the Poker-Chip Principle 



ANEW system of bookless bookkeeping, 

 designed especially for the housewife, 

 happily coincides with the demand for 

 careful record keeping in order to cut down 

 expenditures to a wartime basis. This 

 new system substitutes for old fashioned 

 juggling with figures the simplicity and 

 vividness of account-keeping with poker 

 chips. 



With the new method, books are entirely 

 eliminated. The equipment con- 

 sists of a box containing twenty- 

 eight compartments to show ex- 

 penditures for groceries, meats 

 milk, butter, eggs, and 

 other items of house- 

 hold expense, and 

 seven additional com- 

 partments to hold slips 

 representing various 

 denominations from 

 ten dollars down. 



When a purchase is 

 made, slips indicating 

 the amount are placed 

 in the appropriate 

 compartment. At the 

 end of the month, the 

 housewife can determine 

 the amount soent for 



The "piano" made of a heap of stones (arranged so that the 

 tones of the natural scale are produced by hammer-blows 



each item by counting the amounts, in the 

 different compartments. 



If the article is charged, the right amount 

 is placed in the proper compartment, and a 

 corresponding amount in the "Charged" 

 compartment. Thus there is a correct 

 tab on the amount owed as well as on 

 the expenditures. 



After the housewife has determined by 

 a two or three months' trial about what 

 her normal expenses are for the various 

 items of expenditure, she may change to 

 the budget system. Slips totaling the 

 proper amount are placed in the various 

 compartments, and, as expenditures are 

 made, the amount is removed. The slips 

 remaining show at all 



times the sum left in 

 each "appropriation," 

 so that economy or 

 freedom in spending 

 may be observed. If 

 the slips in any com- 

 partment run short, 

 others may be "bor- 

 rowed" from a com- 

 partment with a sur- 

 plus, a "due" check 

 being put in to show 

 the indebtedness. 

 The amounts remain- 

 ing at the end of the 

 month indicate the sur- 



plus, and the due checks 

 The bookless bookkeeping outfit for the shortages. Thus all 

 housewife who dislikes keeping accounts figuring is eliminated. 



