1872.] between Explosions in Collieries and Weather. 297 



1868. 



The first quarter of this year was very exceptionally stormy, in fact 

 Mr. Buchan, in a paper printed in the 'Atlas Meteorologique ' for 1868, 

 states that during the sixty-three days comprised between the 13th of 

 January and the 26th of March, as many as twenty-seven distinct storms 

 passed over the north of Europe. We attribute thirty accidents which 

 occurred during this period to barometrical causes. 



The first serious depression occurred on the ISth of January, when three 

 explosions were recorded, with a fourth on the 20th ; the barometer re- 

 mained unsteady for some days and reached a very low level on February 1, 

 where we find four explosions close to each other. The disturbances of 

 pressure of the 7th and 19th of February caused, the former two, the latter 

 three explosions, as did also that of March 11th. 



In April the temperature began to rise to a considerable height during 

 the day, so that the amount of daily range was large ; and so we attribute 

 two explosions to this cause. The serious storm of April 21st was 

 accompanied by five accidents. 



A period of warm weather set in in May ; and we attribute the batch of 

 accidents between the 15th and 20th to temperature, and similarly those at 

 the beginning of June and July. Occasionally accidents referable to tem- 

 perature are also reported up to the middle of September. 



After that date we find two months which were comparatively free from 

 explosions, and also from serious storms. The first great disturbance of 

 pressure which succeeded was on the 22nd of November, and it resulted in 

 six explosions, extending over a period of four days. 



The atmosphere was nearly as much disturbed in December as in January, 

 and we count thirteen accidents as due to oscillations of the barometer. 

 The most serious group was that of five, which accompanied the heavy 

 storm of December 21st. 



In all we have in 1868 154 explosions (44 of them fatal), and of these 

 72 seem to be due to changes of pressure, 41 to rise of temperature, while 

 41 appear to us to be more or less independent of either of these agencies. 



1869. 



The first two depressions of the year, those of January 8th and January 

 15th, were each accompanied by explosions, and on the 2/th a period of 

 prolonged violent disturbance set in. Two very marked barometrical 

 oscillations passed over all our stations, bringing with them heavy equato- 

 rial storms on January 28th and February 1st, Seven explosions are re- 

 corded between the 27th and 29th, while the oscillation of the first only 

 caused one. Pressure was very low during the first half of February, the 

 lowest reading being recorded on the 8th, with one explosion, followed by 

 three others on the next three days. 



The storm of February 12th, which was very destructive to shipping in 

 the Channel, was not marked by any colliery accidents, as the oscillation of 



