The present brief summary of activity at Paricutin Volcano, State of Michoacán, Mexico, follows the pattern of the last report on this volcano published in these Transactions late in 1948 [Wilcox and Gutierrez, 1948]. Anticipating the end of his two‐year period of observation at Parícutin in December 1948, Wilcox instructed the junior author, a native Tarascan from the town of San Juan Parangaricutiro, now destroyed, in the processes of keeping detailed diagrammatic records of eruptive activity, of making weather observations, and of outlining the monthly advance of the new lava. On Wilcox's departure the senior author, who had closely followed the series of studies at Paricutin and had frequently visited the Volcano from June 1943 onward, took up the task‐of watching over Paricutin and preparing reports on its activity. During the first six months of 1949 he spent 11 days at the Volcano on the following dates: January 25–28, March 29–April 1, and May 18–20. On these visits he checked the elevations of the chief points on the rim of tie cone, using an alidade at known stations, and in addition followed the growth of the lava‐vent mound, variations in the form of the interior of the crater, and any other features that showed change. Further, he discussed with the junior author, the Volcano's activity during the periods between visits and assembled the observational data for formal presentation.
