Page:Popular Science Monthly Volume 88.djvu/934

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��Popular Science Monthly

���A simple telephone transmitter dragged through the water reveals the nature of the river-bed

��Navigating a River Boat by Sound

TO determine the character of inland river beds, steamboat captains are using microphones installed in sounding leads. On each ship an armored cable leads from the microphone to a telephone receiver and dry batteries. When the sounding-lead drags over the mud bot- tom, a dull groaning sound emanates from the receivers, while a stony or pebbly bottom will cause a series of sharp, staccato raps.

��triangular arm, or fan, which rotates at a high speed, throwing the water upward against the dishes.

After placing the trays with their dishes in the ma- chine, hot water is poured in, the cover adjusted, and the lever operated for two minutes. The soiled water is then drained ofif, fresh boiling water applied, and the operation repeated. The dishes are thus washed and sterilized. They dry of their own accord if the water is hot enough. Of course it is well to scrape the dishes reasonably clean before putting them in the con- tainer.

The convenience of the machine may be increased by a water-pipe connection and a drainage pipe. Also a small motor eliminates the use of the hand-lever in operating the machine.

��Doing Away With the Dish- Cloth

A DISHWASHER has been perfected which does its work quickly and well and which eliminates the unsanitary dish-cloth. The machine consists of a cylindrical container with a diameter of about two feet, funnel-shaped at the bottom and having a tightly-fitting cover to prevent the escape of steam. A wire tray with grooves holds the plates in an upright position, and a central basket contains knives, forks and spoons. After being filled, the tray is placed in the bot- tom of the container. Above it is another tray for the teacups, water- glasses and smaller dishes. Below both trays, in the funnel-shaped bottom is a

���Washing and drying the dinner dishes without a cloth and towel

��If you want further information about the subjects which are taken up in the Popular Science Monthly, write to our Readers' Service Department. We will gladly furnish, free of charge, names of manufacturers of devices described and illustrated.

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