309 
calculated the cost of my plan ; though I am at a loss to 
estimate any source of expense not attending the existing 
modes which mine would incur, I still solemnly believe that 
the practical solution it offers of one of the greatest diffi- 
culties in bringing to the surface our rich stores of fossil 
fuel, unattended with fearful loss of life, should commend it 
to the dispassionate consideration of every coal owner. 
The Paper was illustrated by plans of the different modes 
of working coal pits in use, and a model of Mr. Williamson's 
improvement. 
A discussion ensued, in which Messrs. Briggs, Emble- 
ton, and Jebson took part, gentlemen conversant with the 
working of coal mines, who expressed considerable doubt 
of the practicability of carrying out the views of Mr. 
Williamson. 
