Dr. Oudot, the physician in question, found ten columns in January 1778, the largest of which was 5-1/2 feet high.  The flooring of ice was nowhere more than 15 inches thick, and the parts of the rock which were not covered with ice were perfectly dry.  The thermometer—­M.  Girod-Chantrans used Reaumur, so I suppose that he gives Dr. Oudot’s observations in degrees of Reaumur, though some of the results of that supposition appear to be anomalous—­gave 22 deg.  F. within the cave, and 21 deg.  F. outside.

In April of the same year, the large column had increased in height to the extent of 13 inches; and the floor of ice on which it stood was 1-1/2 inch thicker, and extended over a larger area than before; the thermometer stood at 36 deg..5 F. and 52 deg.  F. respectively in the same positions as in the former case.  In July, the large column had lost 6 inches of its height, and the thermometer gave 38 deg..75 F. and 74 deg..75 F.

In October, the large column was only 3 feet high, and many of the others had disappeared, while their pedestal had become much thinner than it had been in the preceding months.  There was also a considerable amount of mud in the cave, brought down apparently by the heavy rains of autumn.  The thermometer gave 37 deg..6 F. and 63 deg..5 F.

On the 8th of January, 1779, there were nine columns of very beautiful ice, and one of these, as before, was larger than the rest, being 5 feet high and 10 feet in circumference.  The temperatures were 21 deg.  F. and 16 deg..15 F. in the cave and in the open air respectively.

Tradition related that, before the removal of the ice in 1727, one of the columns reached the roof, (Prevost calculated the limits of the height of the cave at 90 and 60 feet,) and this suggested to Dr. Oudot the idea of placing stakes of wood in the heads of the columns he found in the cave, in the hope that ice would thus collect in greater quantities under the fissures of the roof.  Accordingly, he made holes in three of the columns, and established stakes 4, 5, and 10 feet high, returning on the 22nd of February, after an interval of six weeks, to observe the result of his experiment.  He found the two shorter stakes completely masked with ice, forming columns a foot in diameter; and the longest stake, though not entirely concealed by the ice which had collected upon it, was crowned with a beautiful capital of perfectly transparent ice.  The columns which had no stakes fixed upon them had also increased somewhat in size, but not nearly in the same proportion as those which were the subject of Dr. Oudot’s experiment.  The thermometer on this day gave 29 deg..5 F. and 59 deg.  F. as the temperatures.