Measurements of the earth's total magnetic field was conducted on board the HMNZS Endeavour from New Zealand to McMurdo Sound. Measurements were made with a proton magnetometer designed and trialled on this voyage. The magnetic sensing head was towed approximately one ships length astern to remove it from the influence of the ships magnetic field and initially some difficulty was encountered with ... the towing rig. However, most of this was overcome within a day and apart from interruptions due to minor troubles, a practically complete magnetic record over all regions where ice conditions made it possible to tow the sensor was obtained. Seismic profiles measurements at sea was trialled with a view to develop a useable system. During the cruise, two satisfactory methods were evolved. In the first, the cable was slacked using the wire from the bathythermograph winch. Unfortunately the winch broke down. Good records were obtained over representative portions of the ship track, taking measurements at between two and ten minute intervals. The second method was to lay out a two hundred yard manilla rope on the quarterdeck, slack it off and then recover it with the capstan winch. This proved successful except that too many deck hands were needed to handle the rope to make it possible to operate continuously. It was attempted to capture rain water at sea for measurements of tritium however, pure rainwater in the quantities needed for analysis was difficult to obtain.