1. The author acknowledges countless exchanges of ideas with his colleagues on these matters; especially M. Schwartz, J. Steinberger, J-M. Gaillard, D. Tycko, N. Kroll, and J. Rosen. Mr. Warner Hays was invaluable in construction of the equipment.
2. The spark chamber assembly for the Coumbia-BNL neutrino experiment (Gaillard, Goulianos, Mistry, Schwartz, Steinberger) was described in the Berkeley Symposium on Instruments, September 1960.
3. A hydrogen thyratron (KU-153) developed by Kuthe laboratories, which has no baffles and requires anegativegrid bias of ≳300 v, has been fired with delays ≲30 nsec from the driving pulse, reducing the overall delay to ∼180 nsec.