Science: Help for Farmers

> A tractor-drawn stone-picking machine has been invented, whose revolving teeth can remove as much as twelve tons of egg-to head-sized rocks per hour from the top three inches of soil. Produced by Otis F. Reiter, a onetime Maryland farm boy with a piercing memory of stone-picking backaches, the machine has been hailed by farm journals as the greatest agricultural invention since the tractor. In this machine some experts see hope for a revival of Eastern agriculture, whose decline they blame largely on stony soil. Stoneless soil is 18% more productive than soil 30% full of stones.

> New pure breeds of chickens have been developed whose sex can be identified by their markings as soon as they hatch. Sex-sorting of chicks has hitherto been a ticklish and difficult art. Unlike hybrid chicks, in which the sex difference shows up only in the first generation, the new breeds have sex distinctions which persist, according to the researchers who developed them. Developed at Cambridge, England, the new fowls are cherished in Britain, where only egg layers are wanted and it is a waste of food to raise young cocks until they can be identified.