Watertown Arsenal Laboratory, WAL reports. 310/169, 310/172. Electronic signaller to reduce quench-cracking of steel (1st partial report) [with list of references], by L. D. Jaffe, D. C. Buffum, I. L. Preble; [Appendix, Operating guide for electronic quench controllers type 115A and type 115B, with bibliography, by B. Kovarnick].