Heat was brought up by vapor, and in a number of ten-foot holes scattered over the Kilauea floor, the hottest were at the edge of the floor. The Postal Card Crack, near the edge of Halemaumau and 600 feet above red hot intrusives, was exceptionally hot, and it is not at all clear how the water made contact with the hot intrusive rock underneath. This place completely caved in and was lost forever within the enlarged pit of 1924. Sulphur Bank itself is at the edge of an old Kilauea floor on a shelf at a high level. The extra heat at floor edges means a wall crack between the crater fill and the confining funnel, so that hot gas comes up from intrusive lava somewhere deep down toward the center. Thus when a mercurial thermometer was lowered, ten-foot holes would show a hot place half way down and cold rock at the bottom. Some holes had no heat at all, which meant that an inclined steam crack was cut across by the hole or that no steam crack was present. The heat supply was dependent upon vapor channels from heated rainwater, but we were never able, owing to lack of funds, to drill a hole deep enough to find the water supply which made the steam. It is a remarkable fact that the casings on three wells at Sulphur Bank emit continuously a column of steam exactly at the theoretical boiling point for this altitude, as though the groundwater were boiling only a short distance below. Dr. Allen by his analyses proved that Sulphur Bank vapor was ninety-nine percent steam and that the remainder contained fractions of a percent of sulfur and carbon dioxide, but this sulfur was enough in the course of months to coat the interior of our casings with yellow crystals over black iron sulfide. It coated the Sulphur Bank with yellow crystals of sulfur and soaked the rock below to generate brassy iron sulfide. The result of these experiments was to exhibit the complexity of any solfatara in its relation to underground lava, and to the soakage of a volcanic country by rainfall. This is especially important for Martinique and Montserrat.