Study (dated 13 March 2000) concerning the results of the trial with the Caesium Vapour Magnetometer, carried out on 23rd June 1999. The dimensions of the survey area were 40 x 60m. Peter Cott was dissatisfied with the arrangements of the sensing heads for a gradiometer set up and was concerned that the accompanying software was not suitable for archaeological survey. Geomagnetics (the software supplier) analysed the data produced using the ‘Surfer’ software and produced the plot by Peter Cott supplied to CAT and the Museum Service. The Caesium machine located the Romano-Celtic temple, but not the great ditch, or the anomaly that was discovered by Cott in January 2000 when using the Ground Probing Radar.<1><2>