1816.] in some of the Newcastle Coal-Mines. 371 
When I say that the expense of one of my lamps, if made of 
block tin, does not exceed 17s., it is needless to remark that upon 
the score of expense there is no comparison. 
I made many fruitless efforts to descend a mine charged with 
inflammable air. At one time the person who invited me to his 
house, at a considerable distance from Sunderland, went from home 
when Larrived. ‘Two years afterwards, when I arrived at a person’s 
house (likewise at a considerable distance), who had promised to 
descend a colliery with me, I found that he had: just examined all 
the parts of the mine, as he said, and that there was no inflammable 
air to be found in any part of it. ‘This I afterwards found was not 
the case. 
Indeed, the ungenerous opposition I have met with is almost in- 
credible; but the train of miseries detailed in this and my former 
paper leaves no room for delicacy, and the state of the case demands 
that some remedy should be applied. 
_ Inthe mean time all the men of science who came into this 
neighbourhood examined the lamp, and gave it their entire ap- 
proval. ; 
Vexed at such treatment, | wished to forget the subject, and let 
things run their course, when, immediately after an explosion in 
one of the mines, a sensible and humane letter appeared in the 
Morning Chronicle newspaper, signed J. H. H. Holmes, which, 
after much close reasoning upon the subject, put the question 
whether any of my lamps had been used in those coal-mines which 
had recently exploded? 
After a time, and as no person appeared to take up the subject, 
I thought it my duty to state, amongst other things, that no person 
had ever used my lamp in a coal-mine. 
From this public correspondence a private one arose; and not 
long afterwards this Gentleman did me the honour to visit me, and 
immediately commenced an investigation of the coal-mines, in 
order to give some general information upon this very interesting 
subject. 
It will be unnecessary, after the preceding statements, to trouble 
the Royal Society with any further particulars, except the two fol- 
lowing certificates, which were drawn up, and signed, according to 
their respective dates, on the spot where the trials were made, which, 
it is expected, place the value and security of the lamp beyond a 
doubt. The trial within the mine was conducted at the place where 
24 persons were not long since killed by an explosion. 
it 
FIRST CERTIFICATE, 
(Copy.) 
Herrington Mill Pit, Oct. 16, 1815. 
An experiment took place this day on Dr. Clanny’s lamp for pre- 
yenting explosions in coal-mines, It was effected at the mouth of 
