This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol3", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
There are two special advantages possessed by the open visible fire which, though more sentimental than real, have done much to keep the open grate in favour, and are likely to do so for a long period to come. To an engineer's, or any technical mind, the small percentage of heat units obtained from a given weight of coal, and the gross production of soot, must always condemn the open fire, but the average user invariably signifies a strong liking for the cheering effect that the open fire produces ; and the majority argue that radiant heat is preferable to all else. It is quite true that the sight of a cheerful fire is agreeable in cold weather, but if the fire-lover were asked if the visible fire was desirable and pleasing on a summer's day the answer would be in the negative. It is just so in a house properly warmed by hot water or other means ; no desire for a visible fire exists, nor is the thought of it particularly agreeable. It is quite possible, with several means of heating, to have summer to all intents and purposes in the house, day and night, all through the winter, and the open fire is only remembered as a source of dirt, draughts, and extra servants' duties.
In regard to the heat given off by the open fire, this is wholly radiant heat, and its claim for good qualities is based on its being the same as the sun's heat, which also affords radiant heat wholly. Radiant heat, however, is not quite so agreeable as is supposed. Were we to rely wholly on it we should, most of us, perish of cold. This is painfully evident to those who climb high mountains or ascend in balloons. The most agreeable and healthful time a man knows is that of a summer evening, when radiant heat is absent. The pleasant warmth is then due to air that is warmed by the earth and objects which have been heated by the sun. An open fire affords little heat of a generally pleasant character until it has warmed the walls and furnishings of the rooms, and these in turn have warmed the air, and one of the most valuable and universally adopted improvements in open grates has its success based on the fact that it throws heat downwards from the fire on to the floor of the room. No one, male or female, having once experienced hot water, warm air, or steam heat in their homes will ever remember the open fire except as a usually handsome but always a dirt-producing contrivance.
The open grate is a development of the open hearth, which is depicted by Fig. 82, and which was the first form of fireplace, if it can be called such, with which a chimney was used. They are still to be seen and, for burning fallen or split wood and the combustible debris of the country, they serve very well. The heat given off is comparatively small, while the draught induced by these huge chimney openings is such as to make the old-fashioned high-backed settles and chairs a real necessity.
The fireplace which succeeded the open hearth, by natural sequence as will be seen, was the fire-basket- a basket grate, standing on legs upon the hearth, which is now familiarly known as the "Dog-grate." Fig. 83 illustrates a modern type of this grate, still possessing all its original faults, but having favour because of the handsome effect that can be had by its aid. A grate opening, an open hearth about 40 to 50 inches wide, by about 2 feet deep, is prepared, the side and back walls and the hearth being tiled in as fine a manner as the arranged cost will permit. Recently the side walls have been splayed, as the illustration shows, but usually the opening is more square. The dog-grate is then stood in place, and the "fixing" is complete.
The dog-grate affords comparatively little heat for the fuel burned, and, although the appearance is striking, the method of fixing quite commonly causes smoke trouble to arise. It is not down-blow, but what appears to be a want of up-draught, for there occurs a slight oozing of smoke from beneath the mantel frieze, while the general volume of smoke ascends the chimney very sluggishly. The cause of the trouble is the large open air space above the fire, which has the effect of impeding the free passage of the smoke. One remedy for this is the same as that adopted with the old open range (which suffered with the same trouble from the same cause), this being the use of a "blower." With the range the blower consisted of a flat tinware sheet, extending across the upper part of the opening, in front, with a view to causing all air entering the chimney to pass nearer to the fire and so be warmed. With the doggrate the blower, when needed, is arranged in the same way, but it is made of glass, either bevelled plate or leaded glass, in a brass frame. A better remedy, however, can be found in the use of a hood or canopy, with a short flue extending from it, as shown in Fig. 84. An ornamental brass or copper trumpet mouthed hood comes down over the fire to receive the smoke, while its upper end goes through a sheet-iron plate which closes the chimney across, as shown. Under these conditions a dog-grate suffers no more by sluggish draught than an ordinary grate, yet it may stand in a clear tiled opening as a dog-grate re required to do.
It is needless attempting to show the various degrees by which the fixed grate came into use, but it may be of service to show what, until recently, were the ordinary kinds of room fireplaces, if only to describe their faults. Fig 85 shows one of the earlier kinds - a hob-grate, which might be described as a dog-grate fixed between a pair of hobs. It possessed all the faults of the dog-grate (as will be seen at a glance) without the one advantage of the good appearance.
Following this came the "register" grate (Fig. 86). The improvement in this lies in the size and position of the chimney opening, this causing all air to pass close over the fire before entering the chimney, to the exclusion of all cold air getting there. According to old books dealing with this subject, the plate, which is shown closing the chimney opening, could be "set" to remain open to any desired extent, by means of a rod and knob coming through the front. This could be operated at any time while the fire was burning. Later, and within the writer's recollection, the plate had a loosed notched quadrant attached to it, by which the plate could be fixed open to any required extent, this being done while the fire was out. These arrangements undoubtedly gave the prefix "register" as part of the name of the grate, but of late years the plate has had no setting device, and it rests open and useless all the time. The setting of the plate, while the fire was alight, was of real use, as, after a bright fire had been established, the partial closing of the plate checked combustion and caused a noticeable increase in the heat projected into the room. It had to be used discreetly, for if nearly closed when the fire was bright, and left so when the fire was replenished with fresh coal, the room would be filled with smoke in a brief time.