Catastrophe (part forty-seven)
La Catastrophe de la Martinique
Thus at the limit of the volcano’s action, people died of asphyxiation, not burns. An instantaneous death, as with all who were found mutilated, crushed, burned, carbonized, at the heart of this choking, explosive action.
M. Rozé believes Saint-Pierre was destroyed by a torrent of hydrocarbons that descended the mountain with the speed of an avalanche, increased exponentially in force by the volcano’s projection; a torrent that asphyxiated people, and then exploding, burned them.
This accords well with those observations from the officers of the Pouyer-Quertier, from M. Raybaud, 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 village schoolteacher, M. Thierry had seen, “black smoke leap the rim of the volcano through seven new openings, then hurtle down in torrents, where almost at once they covered Saint-Pierre, and exploded.”
What caused these explosions? M. Rozé thinks electrical sparks were created by rapid contact among ashes, vapors, hot gasses, the clouds and air of the atmosphere; that a battery of successive effects so close together composed an event that appeared instantaneous.
What seems a flash of lightning, in the shortest space of time we have the power to see, indeed to imagine, which we call instantaneous, may be rather a succession of lightning strikes produced one after the other, and one by the other. Bearing in mind there is no conceivable limit to the division of time, no more than of space—time is infinite in every case and in every sense. Moreover, without obliging ourselves to explain these electrical discharges, M. Thierry (M. Rozé told me) clearly heard successive blows when the cloud fell on Saint-Pierre.
Some people (added M. Rozé) said the volcanic clouds were of water vapor, and could not conceive that hydrocarbons came from the volcano. But the formation of hydrogen-sulphide and hydrocarbons is easy to explain. This gas forms naturally by the presence of hydrogen in water vapors—in the first case from the sulphur of the volcano; in the second, from 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. Therefore, after the asphyxiation, came the explosion and fire. At the same time, this double electrolysis produced a gaseous rarefaction, that spurred a violent demand for air, explaining certain phenomena of whirling, tearing, etc., which in other cases are explained by explosion and electrocution.
The Meteorological Observations of M. Mirville
The graphics from the registering instruments of the Meteorological Observatory, located at the hospital of Fort-de-France, present some curiosities.
Coinciding precisely with the moment of each eruption, are barometric jolts, high and low, or low and high, no one will ever know; an instant marked by an abrupt vertical measuring a centimeter, its path cut by a dry line, with a half-centimeter above and a half-centimeter below.
I’ll explain the “no one will ever know”. The vertical line is so abrupt, so clean, it is impossible to distinguish the three recorded points that form it. It can’t be told whether they begin from the low or the high position of the recording stylus. No one will ever know if the eruptions of Mount Pelée produced a sudden augmentation of barometric pressure followed by a rapid diminution; or a diminution, followed by augmentation. The only thing certain is that there is an exceedingly rapid variation in the two directions, a variation transcribed by a gap in the course of the recorded curve.
The eruptions were also recorded on the hygrometer. They are transcribed in abrupt descents of dryness, many of these, more rapid and more distinct than those signaled almost regularly in the middle of the day.
The anemometer also carried the mark of the volcanic phenomena. Witnesses who observed the march of the destructive cloud on Saint-Pierre said its path was to the south, and very fast. Saint-Pierre was annihilated because Saint-Pierre is to the south of Mount Pelée. But in strictest terms, the path of the cloud to the south can be explained only by the laws of gravity, the cloud being formed of heavy materials and gasses; and by the configuration of the valleys of the Rivière des Pères and the Rivière Roxelane. Still, an action of wind joined that of the weight. As the anemometer records, 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 course.
This explains, first, the direction of the phenomenon that overtook Saint-Pierre; second, its dispersal over the sea, and the impossibility of docking that held back the first boats to arrive at Saint-Pierre after the fire, etc., etc.
On board the Jouffroy, similar observations were made. They confirmed, further, the craziness of the compass. The same was noted aboard the Suchet. Finally, during later eruptions, when the D’Assas arrived, a vessel carrying the wireless telegraphic apparatus, they noticed very complicated phenomena in its receivers. 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)