I92 DR. S. H. LONG ON “ BLOWING ” WELLS. 
All three wells are domed over, and in the case of one, which 
was originally domed without the insertion of a ventilation- 
pipe, the dome was blown off by the pressure of air within 
the well. 
Repeated observations, by myself and others, have shown 
that air is sometimes being forced out of the well and at other 
times sucked in ; and in connection with one well, where 
a grating is fixed over the end of the ventilation-shaft, the 
sound produced by the air vibrating against this is at times 
so loud that the well is then said to roar, and can be heard 
at a distance of several yards. It is commonly held by the 
inhabitants of the village that the intensity of the roaring 
of this well permits of an accurate forecast of the state of 
the weather. Observations show that this tradition, like 
many other traditions, when they are investigated, rests 
upon a scientific basis of fact. 
“Blowing” wells have been described as occurring in 
several places in England, especially in the North, where the 
geological formation is one of hard rocks ; and such wells have 
been found to connect with cracks or fissures in the rock. 
When the barometer falls the air in these subterranean 
passages is “ sucked ” out into the well and the latter “ blows ” 
outwards. If the fall has been sudden — and it is with such 
a fall that climatic changes usually occur — the exit of air may 
be so great that the well is said to roar. With a rise in the 
barometer the reverse happens, and air is “ drawn ” into the 
well to fill up the partial vacuum that has been formed. In 
the case of the wells at Framingham there is undoubtedly 
a correlation between these barometric changes of pressure 
and the entry and exit of air through the ventilation-pipe 
of the well. Such a correlation has not been measured 
accurately with instruments, but ordinary methods of observa- 
tion have demonstrated that with a fall in the barometer the 
well “ blows ” out, and when the barometer is rising it is 
invariably “ sucking ” in. The movement of air and other 
gases in subterranean passages is a subject that is not yet 
thoroughly worked out, but the above explanation, as applied 
to “blowing” wells, would seem, for want of a better, to be 
a feasible one. 
