...These tests were I believe done using piezo electric gauges which were also capable of reading continuous pressure curves....
Miller, from my reading of Cox you are correct. They were only "handicapped" by not having a digital oscilloscope. However, by increasing the dwell the trace stays visible for some time. They would photograph the trace. Using the photo, they would then hand copy each result to a paper graph. At least that is the presumed method. Cox never gives exact detail except to note the use of piezo gauges.
Pete
