575 
being to escape at the highest, and as experience would 
generally dictate, the most remote part of the workings, 
the question of unventilated goafs will lose much of its 
perplexing uncertainty and alarm, and every other arrange- 
ment attendant on the work of ventilation would so be 
simplified and improved. It would be easy for the purpose 
of strengthening the evidence in favour of direct ventilation 
by means of up-cast at the uppermost " rise," to enter more 
largely into the difficulties and uncertainty which attend in 
practice upon the existing system, with its allied necessities 
of return-air-courses, trappings, and stops. How by friction, 
leakage, and unforeseen casualties which cannot be enume- 
rated, the processes of ventilation may be retarded, and 
perhaps in some degree suspended, to the great peril of 
part if not of the whole mine. But a word or two on other 
aspects of the case must close this paper. 
We remarked at the outset that observations of meteorology 
were also amongst the prominent duties of colliery manage- 
ment. All experience and authority seem to sanction the 
direct influence of temperature, pressure, and other conditions 
of the atmosphere upon the practical ventilation of a colliery 
from time to time. And yet how rarely do we find any 
adequate recognition of this important truth in their manage- 
ment and superintendence. Effective ventilation beino- in 
the strictest sense the vital principle on which everything 
depends, every circumstance which affects it should have 
the closest and most intelligent notice and respect. I have 
observed on several occasions of violent explosion in different 
parts of the country, that they were accompanied by some 
striking variations of atmospheric condition ; and who can 
tell to what useful results it might lead if a careful register 
were kept at every colliery, and returns made to some one 
recognised authority whence all could draw for information 
in the study of the natural laws on which so much of our 
