360 THE ORGUEIL METEOR. 



globe and the air surrounding it. We learn from M. Reichenbach that it would 

 be effective in raising the temperature by 75,000 degrees, supposing that no heat 

 •vras lost by radiation, or by only 5,000 degrees if it ia admitted that it escapes 

 immediately after its production. The real elevation of temperature is therefore 

 included between 5,000 and 75,000 degrees, considerably exceeding anything that 

 we can produce artificiallj. Under these conditions, the globe melts, and the surface 

 becomes covered with this vitreous glaze which is characteristic of the fallen stones. 

 Not only does it melt, but at a temperature of 5,000, iron and carbon burn, throw- 

 ing out brilliant sparks in all directions, and all known substances are reduced to 

 incandescent vapors. The meteorite will then be seen in flames, and will be 

 followed by a fiery train which will give it the appearance of a rocket. This 

 train will then be extinguished, but the substances, which have produced it, re- 

 maining suspended in the atmosphere, will then leave a persistent cloud. If the 

 stone be of email dimensions, as is generally the case, it will be entirely burnt 

 up ; we see a star shoot, reduce itself to smoke, and all is over ; when it is of larger 

 size, it lasts longer, and has a longer path in which we can follow it ; it drives 

 before it the layers of air in its way, and these are compressed, heated, and be- 

 come inflamed. By a contrary reason, it makes a vacuum behind into which the 

 anterior air rushes round the contour of the ball, und the meteorite is thus wholly 

 enveloped in an atmosphere of gas and inflamed vapors. We may pause at this 

 result, as it is of a nature t» relieve our apprehensions. In these meteors it is not 

 the solid part, but the surrounding atmosphere, which we see in flames ; it is this 

 latter which attains such large dimensions, while the nucleus which is hidden 

 from us ia incomparably smaller. This atmosphere has certainly a very menacing 

 appearance, bat it becomes dissipated as soon as the velocity diminishes, and this 

 is why history has had no catastrophe to record, why the fragments are almost 

 always very minute, and why such formidable appearances end in such small 

 realities. 



While the meteor compresses the aii*, this latter by the reaction of resistance 

 presses its anterior face, and if we wish to have an approximate estimation of 

 this force, let us consider what happens during storms. When these reach their 

 most terrible intensity, they have a velocity of 40 metres per second, and exert a 

 pressure equal to 38 lbs. on every square foot of surface exposed to them. This 

 pressure will remain the same, if, by a mere change of relative conditions, we 

 projected with that velocity a meteorite of one square foot anterior surface in the 

 atmosphere at rest ; but, if instead of 40 the velocity were 40,000, the pressure 

 increases in an enormous proportion, and M. Reichenbach tells us that it reaches 

 Too atmospheres at a height of 18 kilometres above the ground. There is nothing 

 but iron which could resist such a pressure without being destroyed. Now 

 these conditions being very similar to those of the Orgueil meteor, it must be 

 admitted that it underwent a similar pressure, and that was the reason why it 

 split suddenly into splinters as a slone does when thrown against a wall. At the 

 moment when this disruption was effected, the whole phantasmagoria of its 

 surrounding atmosphere vanished, and we could at last put a finger, not without 

 astonishment, on the ridiculous cause of so mighty a fuss — some fifty stones 



