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237
Variation in Illuminating Power.— In the Annual
Report of the late Metropolitan Board ot Works, for 1884, it
was stated—as the result of testing with a portable photometer—that
there are parts of London, the inhabitants of
which do not always get their gas of the quality which it was
thought had been secured to them by Act of Parliament; the
gas having been frequently found to be inferior in lighting
power to the prescribed standard, sometimes by as much as
one candle. There is no way of preventing this, the companies
in default being subject to no forfeiture or penalty, as
they are when the gas is shewn to be defective at the regular
testing place. The above facts point to the necessity for an
alteration of the law. The gas referees, it was stated, approve
of the testing of the gas by means of a portable photometer;
and the Metropolitan Board advised the Board of Trade, that
statutory power should be obtained for that mode of testing,
so that the companies may be liable to forfeitures for gas
which the portable photometer shews to be defective in
lighting power.
Standard of Light.—The Metropolitan Board also
suggested the expediency of an alteration in the standard of
light prescribed by the statutes. It is required that the
illuminating power of the gas shall, when consumed at the
rate of five cubic feet an hour, by means of a standard
argand gas burner, be equal in intensity to the light given
by 16 sperm candles of 6 to the pound, each burning at the
rate of 120 grains per hour. A Committee, appointed by the
Board of Trade, reported adversely to the continuance of the
use of the sperm candle as a standard, it having been proved
that, in spite of precautions taken to secure uniformity in the
manufacture of the candles, there remained considerable
variation in their lighting power. In the Report of the
Board for 1887, the subject was again dealt with, and we
were informed that, in the interval, a long series of careful
and complete experiments had been made by the Officers of