Discussion [of "Measurement of the electromagnetic field of waves received during trans-oceanic radio transmission"]

For the further progress of transmission theory it is imperative that a large amount of quantitative data be gathered in different parts of the world, especially on signals coming from great distances. It has become increasingly plain that no single formula can represent the experimental facts correctly at all times. There are factors active in transmission which produce such variations in signals travelling more than two thousand miles (3,200 km.), that on certain days the signals produce current in the receiving antenna in Washington more than fifty times the strength produced on the weakest days. While the original author´s method of measurement is rather complicated, all the observations and necessary precautions appear to have been taken with the greatest care. The only improvement which I can suggest would be a further check on the calibration of the receiving system by sending with a small known antenna current from a portable antenna or loop at a distance of one or two wave lengths from the receiving station. At this distance and with the long wave length used, absorption would not be appreciable, and all the constants and the distance being known, the original calibration could be verified with considerable certainty.