57 
below. As the mines in both “Top” and “Bottom” rock 
were nearly exhausted of brine, the cavities to be filled 
were enormous. Directly beneath where the fall occurred, 
and bordering on an old abandoned Bottom Mine, was a 
rock salt mine being worked. The barrier between the two 
having been on two occasions penetrated, it now gave way, 
and opened a communication with 15 acres of mine having 
a worked-out depth of about 18 feet. Into this mine, down 
a funnel of 100 yards in length from the surface, the water 
rushed with great velocity, causing the lower portion of the 
brook to retrace its course and drain off a large body of 
water from the Biver Weaver and an adjoining lake called 
the Top of the Brook. This immense body of water, 
rushing into the underground cavities, drove out the air 
contained therein, and so violent was the compression of the 
air that it forced its way through every portion of the con- 
tiguous district that was in the least rifted or weak, show- 
ing itself in violent ebullitions in all the neighbouring pits 
and where the earth was fractured, causing a number of 
miniature mud geysers of 10 to 12 feet in height. Much 
property was seriously damaged, and a considerable piece of 
land covered with water. Five sets of salt works are 
stopped owing to the destruction of a road and the pipes 
conveying the brine from the pumping district to the 
works. The greatest sufferers by this subsidence had little 
to do in causing it, and this is one of the great anomalies of 
the system of obtaining salt. The property of numbers of 
persons in no way connected with the salt trade is seriously 
injured, and under the existing law no compensation can be 
obtained. 
This great subsidence is interesting from a geological 
point of view, as showing the action of natural forces, and 
illustrating how change of surface may occur. A counter- 
part of the Old Salt Lake of Triassic times is in process of 
formation. 
