Ovens should always be provided with 2 ventilators, viz., an inlet and an outlet; there are very many ovens with even modern ranges that are only fitted with one ventilator, but a moment’s consideration will show that one ventilator is useless, as you cannot get air to pass out of an oven unless there is a means for a corresponding volume of air to pass in to replace it, and vice versâ, and means should be provided to warm the air as it passes in, for reasons that are obvious. The use of the ventilators is to take off the excess heat, the steam, smells of cooking, &c., from the oven (the outlet ventilator opening into the flue), and by use of the ventilators meat can be either roasted or baked in an oven, the distinction between roasting and baking being that to roast meat the air must have free access to the joint by opening the vents, whereas in baking meat the vents are closed and the meat is cooked in its own vapour, &c.
The former method has the greatest number of advocates, as the results are the same as if it was roasted in front of the fire, provided it has the same attention in basting, &c. It may be here mentioned that in oven-roasting, a water-pan should be used, as it prevents the oven becoming foul by the burning and splashing of fat, and has other advantages; this pan really consists of 2 pans, one fitting within the other, a space of about ½ in. existing between, and a properly constructed meat-stand fitting into the upper one. The joint is put in position on the stand, and the whole is placed in the oven, after which the space between the two is filled with water through an aperture provided for the purpose. These pans are very satisfactory in use, and are now in general favour.
The cleaning of flues should be done once weekly, if the chimney has a good draught, or with hard fuel this time may be exceeded; but it is desirable to say once weekly, as it is then done at regular periods on a certain day; with a very sluggish draught it is sometimes found necessary to clean them a little oftener, as the soot is then nearly all deposited in the flues, and as the fire is longer in becoming bright, more soot is naturally formed (with a bright fire scarcely a particle of soot is formed, the combustion being nearly perfect). The correct method to clean the flues of a kitchen (close fire) range is as follows:—First remove all small flue-doors, loose covers, &c., then draw out the dampers to their full extent, take the flue-brush and pass it first up and then down the flues that are carried up the back of the range, inserting the brush through the openings that are provided just below the dampers; then brush the soot from the tops of the ovens down the flues at the sides; brush down these side flues; and lastly carefully scrape and brush out all the soot that has now accumulated in the flues under the ovens. But it must not be forgotten that the bottom of the oven requires well brushing; this is often omitted, yet it is most important, as in many instances, as before explained, the utmost heat is needed at the bottom, and if it is coated with soot very little heat will pass through, as soot is a fairly good non-conductor of heat. After cleaning the flues, carefully replace all doors, covers, &c.; it cannot too strongly be impressed upon housewives that no opening must be left for the air to pass in, except first passing through the fire. Soot in flues produces two different ill effects, viz., reducing the draught by choking the flues, and preventing the heat coming in proper contact with the oven, as it is a very bad conductor.
The flue-brush for the average of flues should be about 4 in. in diameter at the hair, with a 3 ft. 6 in. or 4 ft. wire handle. Chimneys do not require sweeping nearly so often with close ranges as with open. With an entirely closed range it will with proper care go about 10 to 12 months; with a close range that can be opened (when not cooking) about 7-9 months, varying with different coals, &c. The management of a close-fire range has now been nearly all explained; it may be summed up as follows. At first lighting (after clearing the fire-box of ash, &c., in the usual way), draw out all dampness until the fire is established, after which push in dampers to a more or less extent according to draught. Never permit the fire to make a roaring noise, whether for oven or boiler. If the range has a high-pressure boiler, direct the heat to this until the water is hot, or until the range is required in preparing breakfast. After this meal, the dampers must be pushed in as far as possible to slacken the fire down until it is required for the midday meal (unless the range is required for any other purpose between these times), and the same follows after this meal. There are, however, very many residences where cooking, to a more or less extent is going on all day, in which case the regulation of the dampers must be left to the discretion of the cook. Thoroughly clean the flues at regular periods; if a high-pressure boiler exists, clear the flue under it of cinders, &c., every morning. Thoroughly clean inside the ovens and the oven shelves of any grease, &c., as this is the very general cause of unpleasant smells that pervade the house. When cooking, keep the fire-box well filled with fuel, by feeding it moderately often but in small quantities, as the fire must not be permitted to get low. Do not permit the hot plate to become red-hot; should it do so, push in dampers to decrease the draught, as the fire is burning too fiercely.
Want of draught, which sometimes occurs, and causes an utter failure of the range is due to several causes, the chief of which are:—(a) Other flues running into the kitchen chimney, generally a copper flue, not provided with a damper to close it when not in use. (b) Leakage of air into the flues through some aperture, commonly around the range, caused by imperfect or hurried setting. This can be discovered by holding the flame of a candle near any likely spot, when the flame will be drawn through if any leakage exists. (c) Insufficient height of chimney; about 20 ft. is sufficient for say a 4 ft. range, but the chimney top must be as high as any adjacent building, or impeded or down draught will occur. Suburban villas, &c., are frequently designed with the kitchen situated at the back, in an addition to the main building, this addition generally being lower, in which case, if the chimney is not carried up to the necessary height great inconvenience and annoyance will ensue. Impeded or down draught is sometimes caused by high trees being situated near the chimney. (d) Sooty flues, through want of regular cleaning, or failing to put one of the flue doors in position after cleaning.
The use of the door in the top covering-in plate of the range is, by partially opening it, to take off the objectionable smell when frying, &c.; to reduce the draught to the whole of the range; and for the sweep to operate through when sweeping the chimney.
When a range is newly fixed, it will not give its best results until it has had good use for 6-8 days, as everything around it, the brickwork, &c., is damp and cold. They will sometimes smoke at first lighting, and as ranges differ considerably, a new range requires a certain amount of getting used to. When a range is newly set, the workmen should, before leaving, clear the flues, but this is sometimes neglected, and careless workmen have been known to leave even their tools in the flues.
In instances where a strong draught exists, and the servants cannot be depended upon to regulate the dampers or open the door at top to decrease it, an excellent method is to cut a hole into the flue through the chimney breast above the mantelpiece and there insert a ventilator, but it must be a self-acting one. Arnott’s patent is the best suited for this purpose, as it can be set to a nicety, so that, when the draught is excessive, the valve opens and the chimney gets part of its air, without affecting the fire; this reduces the draught, and then the valve partially or wholly closes, and so it continues. The results are similar to those ensured by the governor on a steam engine, viz., giving uniform regularity to the work.
Fuels.—The ordinary coals of commerce, such as Wallsend, Silkstone, Derby Main, &c., &c., although in general use, are not best adapted for close-fire ranges, which are really furnaces on a small scale, and should be treated as such. Coals such as the above are too highly charged with bitumen (tar), the major portion of which distils off as smoke, fouling the flue, and, as every particle of smoke is unconsumed fuel, there is considerable waste. These coals have also too great a proportion of hydrogen (producing flame) for furnace purposes, as combustion is so rapid; it will be noticed that when burning these soft bituminous coals, upon feeding the fire, volumes of smoke are first given off, after which the fuel fuses into a soft and sometimes sticky mass: this then flames violently for a short period, after which it is time to replenish the fire again. It must not, however, be concluded that fuels entirely free from hydrogen, such as anthracite, coke, charcoal, &c., are well suited for this work, as a fuel free of hydrogen gas burns without flame, and it is found desirable to have some flame, for the heat has to travel some 6 ft. (3 sides of the oven) before its work is performed. It is found that coke and anthracite give an intense local heat (i.e. immediately in or near the fire); but this has an ill effect with the Leamington oven, as making the top of the oven of so much higher a temperature than the bottom, which is fatal to pastry. Where, however, other fuels are not conveniently attainable, coke and anthracite can be used; but the results are not so satisfactory. Coke is almost always used on yachts, so that the sails, decks, &c., may be spotless; but a yacht range is of special make.
Coke, broken to the size of a large walnut, and ordinary coal, mixed in about equal proportions, is found very satisfactory; but the best fuel for close-fire (or the convertible close or open fire) ranges is what is commonly known as hard steam coal; this is not the technical appellation for it, but it is generally recognised by this name, and any good firm of coal merchants stock it, as it is much used for small furnace work. This coal has several advantages, viz., low price (about 16s. to 19s. per ton), much less smoke and soot, more intense heat evolved, and greater length of time in consumption. This is a coal bordering upon anthracite in its nature and composition, but has a moderate percentage of hydrogen; care must be exercised to see that the correct coal is obtained, as should a coal merchant not keep it, he might consider that the low price was the chief consideration and would send a cheap soft coal, which is very unsuitable. This coal has one disadvantage, which is that it cannot be burned in the ordinary open grates unless the grate is provided with a blower, or some means of causing a draught to pass through the fire at first lighting or when heavily fed; it is therefore necessary to have convenience for keeping two sorts of coal.