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Page:Popular Science Monthly Volume 90.djvu/81

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Popular Science Monthly


��A Rain Alarm to Make the Hired Girl Get Up and Close Windows

OXE of the countless young American geniuses for \\hom is waiting the worthy task of carrying out some unrealized ambitions of Thomas Edison, has laid clairn to national atten- tion by the invention of an alarm apparatus which will wake up the housemaid by the loud clanging of a bell when the weather becomes rainy. The sixteen year old Edison in question lives in Minneapolis. His deed was in- spired by his worried mother, who complained that nobody woke up in the night when it rained, and that the water came in at the windows and ruined window curtains, rugs and other household valuables.

The boy, who is a wireless en- thusiast with an inner knowledge of the pranks that the electric current can be made to perform, got but wire, batteries, and tools, confiscated several articles from the kitchen, and set himself to the task.

At the base of one of the gutters leading from the eaves- trough he attached a <ievice for making electric Contact as soon as the first few drops of rain fell. This device consists of a tin funnel beneath which is placed a jelly- glass having two strips of spring-brass attached to its sides and terminating in its (enter. The strips are a.djusted so that, when released, they spring together and send the current from con- veniently located batteries surging through a bell. Crys- tals of coarse salt hold the springs apart. When water touches the crystals they dissolve. Thus contact is made. Even if the salt should not dissolve it will be saturated sufficiently to allow the current to pass.

Wires lead from the brass springs to several dr>^ cells, A bell is located at the head of the housemaid's bed.

The raindrops trickle down the eavestrough to through the funnel and on until tact is made which rings the bell.

���The first drops of rain trickle down from the gutter to the funnel leading to the battery and cause the contact which rings the alarm


���The eight-hour clock designed to abolish computations of time

��the gutter, the con-

��An Eight-Hour Clock for the Eight- Hour Day HARDLY was ink on the eight-hour law dry, when a California watchmaker devised the "eight-hour clock" and at the same time offered a plan for abolishing the confusion arising from the difference in time between various points on the continent. The new clock has but eight figures on the dial, with a small square in the center which shows M from one in the morning until eight; N for noon, and £for evening, the third division. The inventor makes this suggestion: Inaugurate a uniform time all through the United States, and let W^ashington, D. C, be the heart of our time system. The twenty-four hours of the day can be divided into three sets of eight hours and the different divisions indicated as M, N, and £, or Di, D2, and D3. This would eliminate time-computations.

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