For the following valuable statistical details upon gas-light, my readers are indebted to Joseph Hedley, Esq., engineer, of the Alliance Gas Works, Dublin; a gentleman who to a sound knowledge of chemistry, joins such mechanical talent and indefatigable diligence, as qualify him to conduct with success, any great undertaking committed to his care. He has long endeavoured to induce the directors of the London gas-works to employ a better coal, and generate a more richly carburetted gas, which in much smaller quantity would give as brilliant a light, without heating the apartments unpleasantly, as their highly hydrogenated gas now does. Were his judicious views adopted, coal gas would soon supersede oil, and even wax candles, for illuminating private mansions.

Copy of a paper laid before a Committee of the House of Commons, showing not only the relative values of the Gases produced at the undermentioned places, but showing in like manner the relative economy of Gas as produced at the different places, over candles. By Joseph Hedley, Esq.

Names of the Places
where Experiments
were made.
Illuminating
power of a
single Jet of
Gas-flame
four inches
high, taken
by a
comparison
of Shadows.
The Jet of
Gas burnt,
four inches
high,
consumed
per hour
and was
equal to the
Candles
in the last
column.
Gas required
to be equal
to 100 lbs.
of mould
Candles,
6 to the lb.,
9 inches
long each.
[A]
Selling
price
of Gas
per meter
per 1000
cubic feet.
Cost of
Gas equal
in illumi-
nating
power to
100 lbs. of
candles.[B]
Average
discount
allowed
off the
charge
for Gas.
Net cost of
Gas equal
to 100 lbs.
of Candles.
Specific
gravity
of the
Gas.
Equal to
Candles.
Cubic
Feet.
Cubic
Feet.
s.d.L.s.d.Per
Cent.
L.s.d.
Birmingham; -2·5721·2227041001709 147·541
Birmingham and
Staffordshire;
two Companies
Stockport3·254 ·8514891000141112120130·539
Manchester3·060 ·8251536800123111401010·534
Liverpool Old
Company[C]
2·3691·12646100165614149·462
Liverpool New
Gas Company
4·408 ·9116410001186140910·580
Bradford2·1901·23123901811212146·420
Leeds2·970 ·85516448001326140124·530
Sheffield2·4341·0424408001966140183·466
Leicester2·4351·1257576019315 0165·528
Nottingham1·6451·3420090117915 1113·424
Derby1·9371·23521100115415 1100·448
Preston2·1361·153069100110815 162·419
London2·0831·13309210011011none
allowed.
11011·412
[A] 100 lbs. of candles are estimated to burn 5700 hours.
[B] The candles cost 3l. 2s. 6d.
[C] The Liverpool Old Company have since resorted to the use of Cannel coal, and consequently very nearly assimilate to the Liverpool New Company in illuminating power.
Names of the Places
where Experiments
were made.
Illuminating
power of a
single Jet of
Gas-flame
four inches
high, taken
by a
comparison
of Shadows.
The Jet of
Gas burnt,
four inches
high,
consumed
per hour
and was
equal to the
Candles
in the last
column.
Gas required
to be equal
to 100 lbs.
of mould
Candles,
6 to the lb.,
9 inches
long each.
[A]
Selling
price
of Gas
per meter
per 1000
cubic feet.
Equal to
Candles.
Cubic
Feet.
Cubic
Feet.
s.d.
Birmingham; -2·5721·222704100
Birmingham and
Staffordshire;
two Companies
Stockport3·254 ·851489100
Manchester3·060 ·825153680
Liverpool Old
Company[C]
2·3691·12646100
Liverpool New
Gas Company
4·408 ·91164100
Bradford2·1901·2312390
Leeds2·970 ·855164480
Sheffield2·4341·04244080
Leicester2·4351·1257576
Nottingham1·6451·3420090
Derby1·9371·23521100
Preston2·1361·153069100
London2·0831·133092100
[A] 100 lbs. of candles are estimated to burn 5700 hours.
[C] The Liverpool Old Company have since resorted to the use of Cannel coal, and consequently very nearly assimilate to the Liverpool New Company in illuminating power.
Names of the Places
where Experiments
were made.
Cost of
Gas equal
in illumi-
nating
power to
100 lbs. of
candles.[B]
Average
discount
allowed
off the
charge
for Gas.
Net cost of
Gas equal
to 100 lbs.
of Candles.
Specific
gravity
of the
Gas.
L.s.d.Per
Cent.
L.s.d.
Birmingham; -1709 147·541
Birmingham and
Staffordshire;
two Companies
Stockport0141112120130·539
Manchester0123111401010·534
Liverpool Old
Company[C]
165614149·462
Liverpool New
Gas Company
01186140910·580
Bradford1811212146·420
Leeds01326140124·530
Sheffield01966140183·466
Leicester019315 0165·528
Nottingham117915 1113·424
Derby115415 1100·448
Preston110815 162·419
London11011none
allowed.
11011·412
[B] The candles cost 3l. 2s. 6d.
[C] The Liverpool Old Company have since resorted to the use of Cannel coal, and consequently very nearly assimilate to the Liverpool New Company in illuminating power.

Memorandum.—It will not fail to be observed that in deducing the comparative value between candles and gas by these experiments, the single jet (and in every instance, of course, it was the same), has been the medium. This however, though decidedly the most correct way of making the comparative estimate of the illuminating power of the several gases, is highly disadvantageous in the economical comparison, inasmuch as gas burnt in a properly regulated argand burner, with its proper sized glass, air aperture, and sufficient number of holes, gives an advantage in favour of gas consumed in an argand, over a jet burner, of from 30 to 40 per cent. At the same time it must not be overlooked that in many situations where great light is not required, it will be found far more economical to adopt the use of single jets, which by means of swing brackets and light elegant shades, becomes splendid substitutes for candles, in banking establishments, offices, libraries, &c. &c.

Note.—In Glasgow, Edinburgh, Dundee, Perth, and the Scotch towns generally the Parrot or Scotch Cannel coal is used; in illuminating power and specific gravity the gas produced is equal to that from the best description of Cannel coal in England. The price per 1000 cubic feet ranges about 9s., with from 5 to 30 per cent. off for discounts, leaving the net price about 9s. to be equal in the above table to 100 lbs. of candles.

Epitome of Experiments made in Gas produced from different qualities of Coal, and consumed in different kinds of Burners:

Tried at the Sheffield Gas Light Company’s Works, and laid before a Committee of the House of Commons. By Joseph Hedley, Esq.