i 
Fuly 22, 1886 | 
NATURE 267 
and heating purposes, offers many facilities and advant- 
ages over any other kind of fuel. 
Gas Cooking Stoves.—Those who remember the gas 
cooking stoves which were offered to the public even a 
few years ago, will acknowledge that the modern stoves 
now manufactured have reached a very high degree of 
perfection. In nearly all the larger kinds of stove in- 
tended for a family of six or more persons, the sides and 
top of the oven are constructed of double walls, and 
packed with a non-conducting fire-proof material— 
generally slag wool—so that but little heat escapes from 
the exterior of the stove to be lost by radiation; the 
internal surfaces of the stoves are usually enamelled, and 
are thus preserved from rust and decay, and easily kept 
clean, and in addition in some ovens, the racks for 
suspending the grids from which the meat is hung, slide 
out or turn out on a hinge, and are thus more easily 
cleaned than when fixed in the oven. On the tops of the 
stoves are placed burners for boiling kettles and sauce- 
pans, and for stewing, and an invertible burner is some- 
times added, which can be rotated so as to bring the 
flame underneath when it is intended to grill. The 
following points may be enumerated as those in which 
cooking by gas possesses decided advantages over the 
ordinary kitchen range :—(1) There are no dust or 
cinders, and the whole process is more cleanly ; (2) in 
some of the best stoves the oven can be heated up toa 
high temperature—sufficient for making pastry—in a few 
minutes only after the gas is lighted ; (3) the different 
degrees of heat necessary for cooking various articles can 
be easily attained by limiting or increasing the supply of 
gas to the oven burners, or by increasing or diminishing 
the ventilation of the oven by opening or closing the 
flue-valve ; and this is a point which good cooks will 
especially appreciate. 
The principal arguments adduced by the opponents of 
gas cooking may be stated to be:—(1) That the cost is 
greater ; (2) that joints of meat baked in gas ovens smell 
or taste of gas; (3) that the fumes and smell of cooking 
are more perceptible from gas ovens than from ordinary 
kitchen ranges ; (4) that there is no supply of hot water 
with a gas oven ; (5) that the gas stove does not warm the 
kitchen. We will now proceed to consider these objec- 
tions seréatine. 
(1) Although there can be no doubt that more heat is 
obtained from coal by burning the same value than from 
gas, still if attention is paid to the stove, and the gas is 
turned off as soon as the cooking is finished, for ordinary 
sized households the difference in cost between cooking 
by gas and cooking by coal is hardly appreciable. 
(2) We may class gas ovens as of two kinds, A and B. 
In A, rings or rows of burners are placed at the bottom 
of the oven, and the air of the oven is heated up, this heated 
air and the products of combustion of the gas passing over 
and baking the meat. The burners used are usually those 
which give a luminous flame, for the reason that the 
luminous flame, although not itself of so high a 
temperature as the non-luminous flame from the 
atmospheric burner, yet radiates more heat. This 
greater radiation of heat is, like the luminosity, 
due to the separation of solid particles of carbon in the 
flame which become incandescent. Thus we see that the 
luminous flame radiates more heat to the air of the oven 
than the non-luminous. But it is in this class of oven 
especially that the baked meat smells or tastes of gas, as 
it is lable to become sodden with the steam and other 
products of combustion of the gas jets which pass over it, 
and no amount of ventilation of the oven will entirely cure 
this defect. Inthe other class of ovens, B, the burners are 
placed in rows at the bottom and along the sides of the 
oven walls. The oven walls are heated by the flames, 
and when hot radiate the heat to the joint of meat, which 
is thus baked by radiant heat as well as by hot air. The 
the oven and escape by the flue at the back without 
contaminating the meat. Atmospheric burners are 
almost invariably used in this class of oven, because the 
non-luminous flame is hotter than the luminous, and more 
quickly heats the oven wall, although less heat is radiated 
from the flame itself. The atmospheric burners have also 
this advantage, that the gas being mixed with twice its 
volume of air, the hydrogen and carbon are burnt at the 
same time, and no solid particles of carbon are formed, 
and thus there can be no soot from imperfect combustion, 
as so often happens in the luminous flame, in which the 
hydrogen of the hydrocarbons burns before the carbon, 
which is separated into small solid particles and strongly 
heated up before being finally burnt to carbonic acid. 
Consequently meat baked in this class of oven is not 
distinguishable from a joint roasted before an open fire. 
(3) Ifa flue is carried up from the top of the back part 
of the oven into the kitchen chimney, the fumes from the 
oven cannot enter the general air of the kitchen. In all 
gas apparatus of whatever sort, some means must be 
provided for carrying off the products of combustion of 
the gas, and this is especially necessary in the case of gas 
cooking stoves. Ventilation of the oven is obtained by 
air passing in from below to ascend and escape with the 
products of combustion by the flue. The valve guarding 
the flue outlet is capable of regulating the ventilation, and 
is usually so constructed that it cannot entirely close the 
flue. 
(4) The larger gas cooking stoves are now very usually 
supplied with boilers, which can be attached to the side of 
the stove, and can be heated below by a ring of atmospheric 
burners. [The burners at the top of the stove for boiling 
kettles and saucepans, making toast, grilling, and stewing, 
should also be atmospheric.| There can be no doubt that for 
heating a large supply of water, gas is not economical as 
compared with coal, but these boilers have this great 
advantage that they can be easily inspected and cleaned, 
and the fur—caused by the deposit of lime salts where the 
water to be heated is hard—can be easily removed. In 
towns and districts which are supplied with hard water 
(containing much carbonate of lime in solution), the 
ordinary kitchen boiler must be opened occasionally to 
remove the fur—a proceeding causing much inconvenience. 
If the fur deposit is allowed to accumulate too long an 
explosion may take place. This may happen in one of 
two ways; either the mouth of the supply pipe may 
become choked, cutting off the water from the boiler, or 
the boiler plates having become much heated, whilst the 
water in the boiler is cool owing to the intervention of a 
thick non-conducting layer of fur, if this deposit should 
crack, the cold water coming suddedly into contact with 
the red hot iron would cause a dangerous evolution of 
steam. The boilers sent out with gas cooking stoves can 
supply hot water for the kitchen only ; they are not made 
to give a hot water supply under pressure available at any 
part of the house, asis the ordinary kitchen high-pressure 
boiler, so that for upstairs bath and lavatory purposes, 
hot water must be obtained from some form of gas bath- 
heater, of which we will speak presently. 
(5) The gas stoves now made—being well packed and 
losing but little heat by radiation—certainly do not warm 
the general air of the kitchen as the kitchen fire does, 
and this negative quality in summer is a great advantage, 
as the kitchen remains cool instead of being at the usual 
unbearable temperature. In winter. if the kitchen fire is 
retained, this should be lighted early in the day until the 
room is warm, or some form of gas fire may be used—-or it 
is even possible now to obtain a gas stove combining an 
open gas fire below, in front of which a small joint may 
be roasted, with a small gas oven above. The open gas 
fire will sufficiently warm a small kitchen. __ ‘ 
The consumption of gas in a stove of the size required 
for a family of nine or ten persons varies from 15 to 20 
products of combustion of the gasjets pass up the sides of | cubic feet per hour (at an average pressure of 8/r10) if the 
