The smoak of Etna, though very sulphureous, did not appear to me so fetid and disagreeable as that of Vesuvius; but our guide told me, that its quality varies, as I know that of Vesuvius does, according to the quality of the matter then in motion within. The air was so very pure and keen in the whole upper region of Etna, and particularly in the most elevated parts of it, that we had a difficulty in respiration, and that, independent of the sulphureous vapour. I brought two barometers and a thermometer with me from Naples, intending to have left one with a person at the foot of the mountain, whilst we made our observation with the other, at sun-rising, on the summit; but one barometer was unluckily spoilt at sea, and I could find no one expert enough at Catania to repair it: what is extraordinary, I do not recollect having seen a barometer in any part of Sicily. At the foot of Etna, the 24th, when we made our first observation, the quicksilver stood at 27 degrees 4 lines; and the 26th, at the most elevated point of the Volcano, it was at 18 degrees 10 lines. The thermometer, on the first observation at the foot of the mountain was at 84 degrees, and on the second at the crater at 56[22]. The weather had not changed in any respect, and was equally fine and clear, the 24th and 26th. We found it difficult to manage our barometer in the extreme cold and high wind on the top of Etna; but, from the most exact observations we could make in our circumstances, the result was as abovementioned. The Canon assured me, that the perpendicular height of Mount Etna is something more than three Italian miles, and I verily believe it is so.