Abstract :
The surge voltage investigations, 1926 and 1927, are briefly reviewed, and data given for 1928 and 1929. The cathode ray oscillograph has played a prominent part in the last two year´s work, and about 115 oscillograms have been obtained. The following new instruments were introduced in 1929: Lightning stroke recorders; field intensity recorder; and rate of change of field intensity recorder. A vast amount of progress has been made in the solution of the lightning problem. Personnel, equipment, and technique are available for the complete solution of the problem by means of field and laboratory studies, carried on simultaneously and supplementing each other.
