Description of the Process of Manufacturing Coal Gas, for the Lighting of Streets Houses, and Public Buildings / With Elevations, Sections, and Plans of the Most Improved Sorts of Apparatus Now Employed at the Gas Works in London and the Principal Provincial Towns of Great Britain; Accompanied With Comparative Estimates, Exhibiting the Most Economical Mode of Procuring This Species of Light

by Friedrich Christian Accum

Fifteen lamps,—130 feet distance from the main, require a tube 1 inch in the bore.

Twenty lamps,—150 feet distance from the main, require a tube 1¹⁄₄ inch in the bore.

Twenty-five lamps,—180 feet distance from the main, require a tube 1⁵⁄₈ of an inch in the bore.

Thirty lamps,—200 feet distance from the main, require a tube 1¹⁄₂ inch in the bore.

Thirty-five lamps,—250 feet distance from the main, require a tube 1⁵⁄₈ of an inch in the bore.

All copper pipes employed to convey gas through the interior of houses should be of the following weight, with regard to a given length of the pipe:

Bore of the pipe.	Weight per foot.
PARTS OF AN INCH.	OUNCES.
2⁄8	3
3⁄8	5
1⁄2	6
5⁄8	8
3⁄4	10

No coppered pipes should be used but such as have wrapt over and brazed joints. They should be well annealed, to render them pliable without being liable to break.

All the bends for connecting pipes must be circular, see fig. 22, [plate V.]

No branch pipe ought to proceed from a pipe of a quarter of an inch in the bore, and no more than two branch pipes should proceed from a pipe three-eighths of an inch in the bore.