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26
The Gas.—As Chemical Examiner, under the 23rd and 24th Vict,
cap. 125 (1860), the Medical Officer of Health reports:—
From April 1863, to April 1864, the Gas supplied by the Independent
Gas Company, was subjected to 23 separate examinations at the
Testing-office in Kingsland Road, established in compliance with the
Act above cited.
The examination consisted of 10 observations on each occasion, the
gas was burnt at five cubic feet an hour, from an Argand burner of
fifteen holes, with a seven-inch chimney. The Act of Parliament enables
the Company to require three hours notice previous to an examination
being made. But the Company has not insisted upon this right, and my
examinations have been made without notice, and at variable hours,
generally in the evening. The results may therefore be taken with confidence
as giving a fair representation of the quality of the gas supplied.
The average illuminating power was 13.36 candles, being 1.36 candles
above the minimum required by the Act. The maximum power burned
was 14.30 candles; the minimum was 12.50 candles.
During the months of January, February, March, the illuminating
power was never below 13.4 candles, and was on several occasions fully
14 candles. During the months of April and May, the illuminating
power has fallen, but has still maintained an average of 13 candles.
That gas of the highest illuminating power should be supplied during
the winter when the greatest quantity and the greatest light are required,
is most satisfactory: it is, I believe, accounted for by the circumstance,
that in order to meet the extraordinary demand in the winter, it is
generally necessary to use use a large portion of Cannel Coal, an equal
weight of which yields a larger volume of gas, and of much higher illuminating
power, than the ordinary coal which is exclusively used in the
summer.
With regard to the chemical quality of the Independent Gas, I have
never found a trace of Sulphuretted Hydrogen. The means employed
to purify the gas from this form of sulphur-contamination are indeed
perfectly efficient. I have however generally found a small proportion
of ammonia.