From the August 30, 1930, issue

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Wolves in the clothing of sheep have been familiar, at least as metaphors, for a couple of millennia. More lately, since we have begun to pay close attention to our trees and shrubs, have we become acquainted with a tiny wolf disguised as a tiny tuft of cotton. The cottony cushion scale is one of the most bothersome of the parasitic insects that suck the lifesap of plants. The magnifying eye of Cornelia Clarke’s camera has picked up one of these little monsters, and gives us a better idea of the details of his camouflage, as shown on the cover picture of this issue of the Science News-Letter.


A treacherous little stream that flowed down a cliffside and threatened to destroy the prehistoric ruins of Chetro Ketl in Chaco Canyon, New Mexico, has been foiled by a dam that forces the stream to take another course. The rescue of the valuable pueblo ruins was done by two Navajos, by the direction of the University of New Mexico and the School of American Research, which conducted new researches at the site this summer. The stream has caused serious curvature in some of the walls.

The latest excavations show that the pueblo was a story taller than has been supposed, and that it stood five stories tall in its prime.


Boiling mercury will take the place of electric motors and pumps in home refrigerators if a new method just announced here comes into general use. The new process is the invention of Dr. Daniel F. Comstock, president of Comstock and Westcott, and Lyman F. Whitney, of the firm’s technical staff. Dr. Comstock was a former member of the faculty of Massachusetts Institute of Technology and was one of the inventors of the Technicolor process of motion pictures in color.

The machine is called a stator, because all moving machinery has been eliminated. A small boiler contains mercury, and when it is heated and the mercury boils, the vapor is discharged into a venturi tube, sucking water vapor from the cooling unit and compressing it. Under the reduced pressure the remaining water rapidly evaporates, with resultant cooling. The heavy mercury flows back into the boiler and as it does so it pumps the water from the condensed water vapor back to its original height.

Models made so far are operated by gas, but it is stated that an electrically operated unit is contemplated. Besides ordinary uses in home refrigeration, it is stated, the simplicity of the machine will make it available for a home cooling system, to bring low temperatures inexpensively to homes in even the hottest weather.

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