no

RETORTS.

Thick tar.12£ ditto.

Coal used as fuel ....... 4 cwt. 181bs.

Lime for purifying . . . . . . bushel.

Russell’s Wallsend.

Gas of specific gravity ’400 ..... 8600 cubic feet.

Coke ......... 13 cwt. 3 qrs. 14 lbs.

Ammoniacal liquor ...... 12^ gallons.

Thick tar . . . . . . . Ilf ditto.

Coke used as fuel ....... 6 cwt.

Lime for purifying . . . . . . 84 lbs.

In country towns, where the quantity of gas made during the winter season does notexceed 10,000 cubic feet in twenty-four hours, the retorts may be set singly, as representedin Fig. 21, the flue passing beneath and over the retort, which rests upon a half-brick arch,cut flat at the top to receive it; the end being guarded by a thick fire-tile.

Fig. 21.

lop flue

When the quantity of gas made in twenty-four hours does.not exceed 30,000 cubic feet,or when the quantity made is decreased 1200 cubic feet at a time, on the approach ofsummer, the ovens may contain two retorts, as shown in the annexed woodcut. The fluesare arranged in a similar manner to those in a large oven.

The Fuel used for heating the retorts may be either coal or coke, according to the rela-tive value of each in the district. If coal is used, a well-regulated bench will require about18 to 20 lbs. for each 100 lbs. of coal distilled. The use of coke as fuel is more general,particularly in those places where coal is valuable, as in the neighbourhood of London, andwhere coke is less in requisition as fuel for manufactures. The quantity of coke for heating