I willingly accepted the proposal, and Captain Kater offered to accom­pany me. Sir Thomas Lawrence, who was suffering from indis­po­si­tion, did not think it prudent to join our party. In fact, he died on the second or third day after our exper­i­ment.

The iron folding-doors of the small room or oven were {214} opened. Captain Kater and myself entered, and they were then closed upon us. The further corner of the room, which was paved with squared stones, was visibly of a dull-red heat. The thermometer marked, if I recollect rightly, 265°. The pulse was quickened, and I ought to have counted but did not count the number of inspirations per minute. Perspiration commenced immediately and was very copious. We remained, I believe, about five or six minutes without very great discomfort, and I experienced no subsequent inconvenience from the result of the experiment.

A Living Volcano.

I have never been so fortunate as to be conscious of having experienced the least shock of an earthquake, although, when a town had been destroyed in Ischia I hastened on from Rome in the hope of getting a slight shake. My passion was disappointed, so I consoled myself by a flirtation with a volcano.

〈VESUVIUS—CORONETS OF SMOKE.〉

The situation of my apartments during my residence at Naples enabled me constantly to see the cone of Vesuvius, and the continual projections of matter from its crater. Amongst these were oc­ca­sion­al­ly certain globes of air, or of some gas, which, being shot upwards to a great height above the cone, spread out into huge coronets of smoke, having a singular motion amongst their particles.

A similar phenomenon sometimes occurs on a small scale during the firing of heavy ordnance. I have frequently seen such at Plymouth and elsewhere; but I was not satisfied about the cause of this phenomenon. I was told that it occurred more frequently if the muzzle of the gun were rubbed with grease; but this did not always succeed.

〈ARTIFICIAL IMITATION.〉

Soon after my return to London I made a kind of drum, by {215} stretching wet parchment over a large tin funnel. On directing the point of the funnel at a candle placed a few feet distant, and giving a smart blow upon the parchment, it is observed that the candle is immediately extinguished.

This arises from what is called an air shot. In fact, the air in the tubular part is projected bodily forward, and so blows out the candle. The statements about persons being killed by cannon balls passing close to but not touching them, if true, are probably the results of air shots.