DeLand pool. Improvised foundry, Daytona Beach. Making a part for the new type of air raid siren he invented. Several years ago, city fireman J.L. Clayton of Daytona Beach, Florida, became interested in melting alloys and built a hobby foundry in back of the fire station where he spent his spare time. Now it has grown into a three-man foundry at the edge of town, and he is turning out experimental parts for bombers, vital pieces for the DeLand industrial pool, and air raid sirens of aluminum and brass