Page:Popular Science Monthly Volume 89.djvu/471

 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.

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��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 the 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.

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