The gas-flame used in gas cooking-stoves differs essentially from the ordinary gas-flame used for lighting purposes. It is necessary to bear this in mind, for some persons object to gas-cooking because they are only acquainted with gas in the form used for illumination, in which it is capable of giving off so much soot and other objectionable products of combustion. In the gas cooking-flame the combustion is more perfect, and consequently the temperature is very much higher, so that by this simple change an extraordinary saving of gas is effected, while the objectionable products before mentioned are almost entirely eliminated. To effect this change, all that is necessary is to mix the gas with a sufficient quantity of air before it reaches the flame, and to subdivide the flame itself. This mixture of gas and air has been for a long period in use for heating purposes in the laboratory of the chemist under the form of the Bunsen burner, and also in the blowpipe, and is almost indispensable to him.
The advantages which gas possesses over coal and peat for cooking purposes may be summed up as follow: (1) It is always ready, and can be turned on and off in a moment; (2) It is very clean, deposits no soot if properly lighted; (3) The heat can be regulated to the requirements of the occasion; (4) It requires no attention; (5) It is cheap and economical; (6) It preserves the flavour of meat; and (7) It saves time and labour.
Any person who considers the amount of labour and time expended in connection with ordinary fires—the comparative difficulty of lighting them—the frequent attention necessary to maintain them, and the waste of fuel when not in use—the amount of soot they discharge about the compartment, and deposit, more particularly in open stoves, on the utensils used in cooking—the absence of any means by which the heat can be properly regulated—cannot fail to be convinced that coal for cooking purposes has a great rival in gas. That gas is economical cannot for a moment be disputed, even when the question of labour is not included. Of course the comparison will vary in different localities; but wherever the price of gas is in proportion to the price of coal—that is to say, wherever no exceptionally high price is charged for the cost of manufacturing gas—the cost of cooking by the latter will compare favourably with that of coal. A few figures taken from actual trial will make this clear. A ton of Wallsend coals in London costs twenty-six shillings, and will feed a small kitchen stove for two months; making the charge thirteen shillings a month. To this must be added one shilling a month for firewood, which costs in London three shillings and sixpence per hundred bundles. This amounts to fourteen shillings a month. The cost of gas for doing the same amount of cooking amounts, at three shillings per thousand cubic feet, to, say, fourpence a day, or ten shillings a month; to which eightpence a month for rent of gas-stove has to be added. This amounts to ten shillings and eightpence; making the saving per month upwards of three shillings. Where stoves can be had for hire from the Gas Companies—and they can now be had from most Companies—hiring is cheaper than purchase. Moreover, the Company keep them in repair without extra cost.
The advantages of gas are felt chiefly in summer, when coal-fires are not only not required for heating purposes, but when kept lighted all day, are positively objectionable; and to the workers in the kitchen almost intolerable. The atmosphere of a kitchen where gas is used at this season contrasts strongly in temperature with that of one in which coal is burned. When coal-fires are kept up only for the preparation of each meal, the cost of relighting is somewhat considerable.
There are many objections offered to the use of gas for cooking. It is very commonly said that an offensive smell is imparted to the victuals cooked by gas—that gas is really more costly in the end—and that the statements made by gas and gas-stove manufacturers in respect to working cost are lower than can be obtained in practice. If the stove be a good one, the victuals are generally better cooked than by the ordinary method; there is no objectionable smell, and no objectionable taste. The flavour of meat roasted or baked in a good stove is superior, because it can be done quickly, and is not allowed to toughen, as frequently happens before a low kitchen fire. That gas is not more costly than coals is proved by the figures given above.
We will conclude by saying a few words about stoves. It should be seen that means are provided for supplying a sufficient quantity of air for admixture with the gas before it reaches the flame. The air is admitted through a number of holes or slits opening into the tube through which the gas passes, and in rushing forward under pressure the gas draws the air with it into the flame. To realise a maximum amount of heat out of a given quantity of gas, it is necessary to add to it a definite proportion of air. When the gas rushes rapidly towards the flame, a greater quantity of air is drawn in through the orifices provided for that purpose than when the gas passes more slowly. This to a certain extent regulates the supply of air; but it sometimes happens that too much or too little air is admitted. A small quantity of gas passing through the pipe cannot exercise the force necessary to create a partial vacuum into which the air would be drawn, and as a consequence, the heat derived from the flame is far below what might be expected—in short, it ceases wholly or partially to be a blue flame, and becomes a luminous and comparatively cold, or perhaps a smoky one. The other provision is made for the proper control of the supply of air; and since an excess is the lesser of the two evils, it is wiser to adopt the precaution of having holes or slits in the pipe large enough to admit a sufficient quantity of air. The larger the oven or roaster, the more convenient it will be. This oven should be provided with movable ‘grids’ or trays, and should have one metal tray for the reflection of heat, by which the tops of pies, &c., may be browned; and also with a ventilator, to allow the gases to escape. A gas-stove with a small oven, or with one divided into a number of parts without the means of being enlarged, will be found very inconvenient if it is required to roast a large joint.
A BUTTERFLY IN THE CITY.
Fair creature of a few short sunny hours,
Sweet guileless fay,
Whence flittest thou, from what bright world of flowers,