La Catastrophe de la Martinique: forty-seven
Thus, at the limit of the phenomenon’s action, the people had died of asphyxiation, not burns. And instantaneous death, as with all who had been found mutilated, crushed, burned, carbonized, at the heart of this asphyxiating, explosive action.
M. Rozé believes that Saint-Pierre was destroyed by a torrent of hydrocarbons that descended the mountain with the speed of an avalanche, increased tenfold in force by the volcano’s projection, a torrent which asphyxiated the people, and then exploding, burned them.
This accords well with those observations characteristic of the officers of the Pouyer-Quertier, of M. Raybaud, of M. Clerc, etc.
M. Rozé has given me a piece of news, by way of M. Thierry, inspector of secondary crops at the Morne-Rouge. With the town schoolteacher, M. Thierry had seen, “black smoke to leap the cap of the volcano, then, by seven new openings, to hurtle in torrents that covered Saint-Pierre almost at once, where they exploded.”
What caused the explosion? M. Rozé thinks electrical sparks instigated an exceedingly rapid contact among the ashes, the vapors, the hot gasses, the clouds and air of the atmosphere; that a battery of successive effects so close together completed an action appearing instantaneous.
By what to us seems a blaze of lightning, in the shortest space of time we have the power to appreciate, indeed to imagine, and that we call instantaneous, it may be rather a succession of lightning strikes that produce themselves one after the other, and one by the other. Let us not forget that there is no conceivable limit to the division of time, no more than of space…that it is infinite in every case and in every sense. Moreover, without obliging ourselves to go so far as to explain the succession of electrical discharges, M. Thierry (M. Rozé told me) clearly heard successive blows when the cloud came on Saint-Pierre.
Some people, added M. Rozé, said that the volcanic clouds were of water vapor, and did not conceive that hydrocarbons came from the volcano. It is, however, easy to explain the formation of hydrogen-sulphide and hydrocarbons. This gas can form naturally by the action of hydrogen from water vapors, in the first place by the sulphur of the volcano; in the second, by the carbon in the soil.
These streams of gas charged with a given electricity, making contact with the atmospheric gasses carrying a different electrical charge, can produce sparking. This sparking decomposes the two groups of gasses. The hydrogen of the volcanic gas is set free. The oxygen in the air also. Hence, after the asphyxiation, the explosion and the fire. At the same time, this double electrolysis has produced a gaseous rarefaction, that spurs a violent demand for air, explaining certain phenomena of whirling, tearing, etc., which phenomena elsewhere are also explained by explosion, by electrocution.
The Meteorological Observations of M. Mirville
The graphics from the registering instruments of the Meteorological Observatory at the hospital of Fort-de-France present some curious particularities.
Coinciding precisely with the moment of each eruption, were barometric jolts, high and low, or low and high, no one will ever know, with an abrupt instantaneousness; jolts marked by a vertical of a centimeter, its path cut by a dry line, a half-centimeter above and a half-centimeter below.
I explain the “no one will ever know”. The vertical line is so abrupt, so clean, so instantaneous that is impossible to distinguish the three points recorded from which it is formed. One cannot distinguish if they begin from the low or the high position of the recording stylus; thus, no one will ever know if the eruptions of Mount Pelée, in their action on the barometric pressure, had produced a sudden augmentation followed by so rapid a diminution; or, inversely, by a diminution, then an augmentation. The only thing certain is that there is an exceedingly rapid variation in the two directions, a variation transcribed by a cutting in the course of the recorded curve.
The eruptions were also recorded on the hygrometer. They are transcribed by abrupt descents of dryness, many, more rapid and more clear, than those signaled almost regularly in the middle of the day.
The anemometer carried, this also, the mark of the volcanic phenomena. Those witnesses who had observed the march of the destructive cloud on Saint-Pierre said that its path was towards the south, very quick. And it must be for that Saint-Pierre was annihilated, because Saint-Pierre is to the south of Mount Pelée. But, in strictest terms, this march of the cloud to the south, could be explained by only the laws of gravity, and the configuration of the valleys of the Rivière des Pères and the Rivière Roxelane, the cloud being formed of heavy materials and gasses. Nevertheless, the action of the wind joined that of the weight. And as the anemometer records at the hospital, the direction is marked ordinarily by a line tending to the northeast. At the hour of the eruption, the line jumped suddenly to the south, before taking, a little afterwards, its habitual direction.
And this explains: 1st, the direction of the phenomenon that overtook Saint-Pierre; 2nd, its dispersal over the sea, and the impossibility of docking which kept back the first boats arriving to land at Saint-Pierre after the fire, etc., etc.
On board the Jouffroy, similar observations were made. They confirmed, further, the craziness of the compass. Equally, aboard the Suchet. Finally, during later eruptions, when the D’Assas arrived, which vessel carried the wireless telegraphic apparatus, they noticed very complicated phenomena in the receivers of this. An officer told me the antennas of the ship were singing.
Anemometer: Instrument used to measure wind speed.
Decomposition: (chemistry) The separation from a compound of individual elements, such as a metal oxide and a gas.
Electrolysis: A chemical reaction caused by the introduction of an electric current.
Hygrometer: Instrument used to measure atmospheric humidity and water vapor content.
Rarefaction: A reduction in density, such as in the air’s oxygen at higher altitudes.
(As today’s episode records, the wireless was just beginning to be used in 1902; its role in the Titanic rescue led to a rapid adoption worldwide.)
(1902, Jean Hess, La Catastrophe de la Martinique; 2019, translation, Stephanie Foster)