Popular Scic7ice Monthly 



water in the pan surrounding the 

 outer shell causes the water to 

 flow up ill the air space l)ctwecn 

 the shells. The result is that 

 the air within the water cooler is 

 more rarefied than the air with- 

 out. 



At the same time, warm air on 

 the outside of the shell, and cool 

 air on the inside, produces con- 

 densation, which also assists in 

 lowering the temperature with- 

 in, the degree of cooling being 

 dependent on the rarefication 

 and amount of condensation pro- 

 duced. It is this principle which 

 is employed in the iVIe.xican Oya, 

 or water bottle, which is made of 

 thick porous clay which "sweats" 

 profusely, cooling the water within. 



A Typewriter Desk Made from a 

 Kitchen Table 



A KITCHEN table was converted 

 into a typewriter desk in the fol- 

 lowing manner: An i8-in. by 24-in. 

 bread-board was purchased from the 

 hardware store and some pieces of i-in. 

 by 2-in. soft wood obtained. Two pieces 

 of the latter were placed across the under 

 side of the table, from the back to the 

 front boards, serving as guides for the 

 bread-board. Two more pieces were 

 fastened to the board near one end and 

 arranged to fit o\-er the side pieces. 



The board was put in place as a shelf 

 under the table and a final cross strip 

 of the I -in. by 2-in. board was fastened 

 to hold the front in place and allow the 

 board to slide under the lower edge of 

 the front board. — E. W. Hyman. 



457 



POSITION FIXtDTD WALL 



BREAD BOARD 1X2" , 

 GUlDtS FOR BOARD 1X2"' ; 

 5TR1P l>2-rOHOLD BOARd' 

 TWO STRIPS llJ?'' FASTENED ON , 

 BOARD TO SLIDE ON THE GUIDES' 



A Shelf of Correct Height for tiie Typewriter 

 Has Been Added to the Table 



SLIT FOR MATCH 

 SEMICIRCULAR OPENINO 

 IN E.ND OF INNER CASE 



I This Position the Matches Gravitate to the 

 Lower Exposure End of the Box 



A Simple and Convenient Recep- 

 tacle for Matches 

 A MATCHBOX which does not have 

 to be opened and from which only 

 one match at a time can be extracted, is 

 shown in detail in the accompanying 

 illustration. 



The ordinary sliding carton is a most 

 unsatisfactory contrivance for the reason 

 that the greatest care must be exercised 

 in opening it and removing the retard- 

 ing strip. Every time a match is re- 

 quired both hands are necessary to open 

 the box and extract it. 



The new box has at one end and in the 

 bottom a cut-out portion so as to expose 

 the matches, only the ends being sup- 

 ported against the uncut portions of the 

 box. In the corners, however, the box 

 is slit so as to provide a means for 

 drawing out the match. 



In use the box should be secured to 

 some object on the wall or wainscot at 

 an angle by means of small nails driven 

 in the upper corners. In that position 

 all the matches will gravitate to the 

 lower exposure end of the box in position 

 to be grasped by the thumb and fore- 

 finger. 



It is not a difificult matter to convert 

 the ordinary box into a receptacle of 

 this kind for permanent attachment to 

 the wall. The sectional view shows how 

 this may be done. In order to refill it 

 from a new box the inner sliding portion 

 only is removed, and when filled it is 

 returned to the stationary case which is 

 fastened on the wall. 



