354
JOURNAL
on CHEMICAL EDUCATION
MMCH, 1928
Self-winding Clock Run by Thermometer. A self-winding dock, run by what is virtually a glycerin thermometer, has been invented by a Swissengineer, Karl Heinrich Meier. It utilizes the energy captured by the daily fluctuations in temperature t o raise the weights that drive its mechanism, and it is stated that one of the clocks has been kept going for a year on a daily range of not more than eight degrees Fahrenheit. The essential mechanism consists of a long coiled tube filled with glycerin, connected with a cylinder into which a piston is fitted. When the glycerin is warmed and expands, it forces out the piston, which in turn lifts the clock weight. It is expected that this device will be especially useful in operating outdoor clocks in public places. The types now in common use are usually electrically driven and are, therefore, expensivet o install, besides requiring frequent attention.-Science Service Hot Springs Minerals Laid Down Rapidly. The deposits of hot springs limestone, more properly known as "sinter," are laid down very rapidly, according to Margaret Lindsley,of theYellowstoneranger staff,who has been making a study of the phenomena in the park for the geophysical laboratory of the Carnegie Institution of Washington. She writes of one of her observations: "A little wooden cylinder made expressly for measuring the rate of deposition was wired in place near the foot of Jupiter Terrace. This point is easily 300 feet from the n na t the too and only about 5 feet above the main hiahway. The water in hot s.~ r i . tumbling down over the terrace is well seated and cooled t o a little above body temperature. The block and the wire which held i t in place were removed 21 days Later, covered with a deposit of chalk-like travertine to a thickness of from one-half tothree-fourths of an inch. One miaht think that the water would lase most of its burden of mineral by the time i t was a t so great a distance from the point of emergence, but the experiment proves that such is not the case."-Science Service German Factory Smoke Injures Field Crops. The Ruhr industrial region, recently restored to normal operation following the withdrawal of the French, has given a striking illustration of the damage wrought by factory smoke, not only t o trees and gardens in the cities but t o the farm crops throughout the countryside. When the French occupied the region in 1923 the Germans adopted a policy of "passive resistance," dasing down all the factories. With the air cleared of its load of smoke and acid fumes, the farms of the Ruhr valley yielded full crops for the first time in many years. Then the French withdrew and the chimneys started smoking again, and now the oops have dropped back to their previous low level.-Science Service Cadmium Metal Finds Use in Solders. Cadmium, chemical brother to zinc, is finding a useful place in industry as one of the components of special solders, Carl E. Swartz, metallurgist of Selby, Calif., told the American Institute of Mining and Metallurgical Engineers a t New York recently. Lead, tin, and zinc are the metals used in such common solders as those in sealing tin cans, but where lithographed labels are used on tin cans a special solder containing cadmium is now used because its lower melting point prevents dismloration of the lithographing.-Science Service Watercress Has Manv Vitamins. The list of foods the doctor says you should eat has been augmented by a new one, watercress. This familiar aarnish for meat and salad is a remarkably rich source of the vitamin necessary for growth and of the scurvy-preventing vitamin C, Dr. Katherine H. Coward and P. Eggleton, of the University of London, have found. It boasts of small quantities of vitamin D as well in its small green leaves. The green shows considerable seasonal variation, however, in its growth-promoting properties, the investigators have found, being more effective with laboratory animals in this resped in spring and summer than in winter.-Sience Service ~
