1887.] The Detonating Bolide of November 20, 1887. 263 



The above show that the parabolic form seems to be followed, but 

 owing to the want of absolute uniformity in all parts of a photographic 

 plate, and that errors may arise from want of exact exposure, and, 

 again, from reading the densities, the values obtained are not so 

 accordant as those taken by the visual method. 



V. "On the Detonating Bolide of November 20th, 1887." By 

 G. J. SYMONTS, F.R.S. Received December 8, 1887. 



Shortly after November 20th it was generally reported that an 

 earthquake shock had been felt in the South Midland counties of 

 England, and the author began to collect and examine the facts. Jt 

 appeared that the records from Oxfordshire, and the western stations 

 generally, indicated that much louder sounds were heard there than 

 at the eastern stations, e.g., Essex and Cambridge. The author 

 thought that, although the phenomenon had been almost universally 

 ascribed to an earthquake, it was more probably due to an explosive 

 bolide, and on receiving from one of the local scientific societies a 

 request for assistance in tracing the shock, the author suggested the 

 alternative explanation. Mr. Fordham has subsequently written to 

 say that he has already found one person who saw the meteor from. 

 Hertford, which he describes as " a brilliantly luminous body travel- 

 ling across the sky from N.E. to W." It is further stated that a 

 portion of the meteor was seen to fall from the main body. 



Considering that the morning, as shown by the records of the Royal 

 Meteorological Society, was both misty and cloudy, and that at the 

 hour at which it appeared, Sunday morning, 8.20 a.m., there would 

 be broad daylight, it is improbable that many persons saw it. Judg- 

 ing by the descriptions of the noise, as well as by the path roughly 

 indicated by the Hertford observation, it seems likely that it ex- 



