Fort Vancouver
Historic Furnishings Report: Bakery
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CHAPTER III:
COMPARATIVE DATA: OVENS

The available specific data show that the Fort Vancouver bakery of 1844 contained two brick ovens, each having a chimney at its west end. Archeological evidence proves that they were placed side by side on cobblestone foundations 1.6 feet to 2.0 feet wide enclosing a space with outside dimensions of about 25.0 feet north-south and 15.0 feet east-west. From information found in inventories it is almost certain that tiles were employed in the oven structures in addition to brick, very probably at least on the oven floors since, as has been seen in the previous chapter, tiles were often used for this purpose in ovens in which biscuits were baked. [1]

But most other construction details remain unknown. Among them are the thickness of the oven walls, the interior shape and dimensions of each oven, the height of the oven floors above the ground, the height of the oven arches, whether the chimney entrances were within or without the oven doors, whether there were arches under the ovens, and how far apart the ovens were. In a reconstruction such features will have to be designed upon the basis of the general practice of the time as determined by available comparative data.

For assistance in determining what the general practice was, if indeed there was one, there are presented below descriptions of ovens believed to be of about the same size, type, and function as those at Fort Vancouver. Since the basic design of wood-burning ovens did not change greatly during the eighteenth and nineteenth centuries the dates of the examples are not of major importance for our purposes. On the other hand, the cultural heritages reflected in the designs do appear significant to a certain degree.

This conclusion brings up a difficult question. Did the ovens at Fort Vancouver reflect the national backgrounds of the predominantly Scottish officers at the post or of the French Canadians who operated and probably actually constructed the bakery? No decision seems possible, but the present writer is inclined to feel that the officers did the designing, perhaps on the basis of some English precedent, plan, or manual as yet unidentified.


Ovens at Lower Fort Garry, Manitoba

In the Historic Structures Report Historical Data Fort Vancouver, vol. I, pp. 53-54, it was suggested that the two existing sets of bake ovens (three bakery structures survive, but only two have ovens) at the Hudson's Bay Company's Lower Fort Garry on Red River might serve as models to a certain extent for several features of the reconstructed Fort Vancouver ovens. That suggestion still seems to have a degree of validity, but caution must be used in accepting the theory that the Fort Garry ovens faithfully reflect oven technology at Company posts during the mid-1800's.

Since the Historic Structures Report was written, it has been learned that the ovens which must have most closely resembled the ones at Fort Vancouver, those in the Northwest Bastion, probably originally dated from the period 1846-1848 rather than 1831-1847 as heretofore understood. This fact would not of itself present a serious problem, but it is now apparent that every trace of the original 1846-1848 ovens may have been removed from the bastion in 1911. [2]

The present ovens in the Northwest Bastion, therefore, are reconstructions. The evidence used as the basis for the rebuilding is not clear to the present writer, but the extant ovens so well correspond with general descriptions of bake ovens of the period that apparently a serious effort was made to achieve accuracy in restoration. [3]

At any rate, the information on the twin ovens in the Northwest Bastion is repeated here for what it is worth. This oven complex was considerably smaller than that at Fort Vancouver, the outside dimensions of the foundations being about 14'9" x 8'8". Each of the two baking chambers was rectangular in shape, 5' long and 4'3" wide, with a vaulted ceiling about 3'3" high at the top of the arch.

The ovens were built largely of stone, though some brick was used about the oven entries. The ovens were vaulted on the outside as well as inside, being placed side by side with a common wall about three feet thick between them. The side and rear oven walls were somewhat more than a foot thick, while the common front wall was about 2'8" through. The floors (or hearths as they were termed) of the baking chambers were level with the bottoms of the doors. A flue led in a slanting direction from the top front of each oven to a common chimney at the front end of the ovens. Air spaces at the sides and rear of the joined ovens separated the heated elements from the walls of the bakery.

diagram
Figure 4. Diagram of one of two baking chambers in the Stable, Lower Fort Garry.

The construction of these twin ovens is illustrated by the photographs in Plates III and IV. Further details are given in Plate V, a drawing based on measurements made during a visit to Fort Garry by Architect A. L. Koue and Historian J. A. Hussey on September 20, 1967.

There is a second bakery at Lower Fort Garry, located in a building designated as the Men's House or Stable. Although this complex of two separate ovens appears to date from a later period of military occupancy, it has features which may be applicable at Fort Vancouver. In particular, the height of the oven hearths above the bakery floor, 40 inches, would seem more suitable for large-scale bakery operations than the back-breaking 24 inches of the Northwest Bastion ovens. The dimensions and general design of one of these ovens are shown in Figure 4 on the following page. What apparently is a photograph of these ovens before restoration is shown in Plate VI.


An "ordinary" British baker's oven

According to one authority, the "ordinary" baker's oven in Britain was a vaulted chamber, about 10 feet long, 8 feet wide, and 30 inches high at the top of the arch. [4] A perusal of a number of sources concerning early baking in England confirms this very general observation and adds the further information that the baking chamber was sometimes oval in shape and sometimes rectangular, one not being obviously favored more than the other.

But when one comes across some of the very few available detailed descriptions of British ovens, it is difficult to find a reflection of this general picture in the specifications given. Perhaps the reason lies in the fact that the persons who prepared these descriptions were more interested in advocating new or "improved" models of ovens than in depicting the more common, antiquated types.

Such may have been the case with John Claudius Loudon, an industrious compiler of handbooks on agriculture and architecture. In his book Cottage, Farm, and Villa Architecture, published in 1844, he presented a plan for a "common country oven," which he described as "a rude kind of oven adapted for new countries, where it is frequently necessary to use for fuel green boughs."

In his introductory remarks before describing this oven, Loudon stated, "The ordinary size of Bakers' ovens is from eight to twelve feet square . . . . The height of a baker's oven is about eighteen inches in the centre, in ovens of the smallest size, and two feet in those which are larger. "The lower and flatter the arch is, he continued, "the more easily is the oven heated, and the more equally does it give out its heat. The sides of the oven need never be higher than a foot . . . and there can be no reason why the roof of the oven should be higher in the centre than at the sides, except that it is impossible to build the soffit of an arch perfectly flat. The floor of the oven is laid with tile, and the arch is formed of fire-brick, fire-stone, or trap, set in fire-clay, or in loam mixed with powdered brick. The whole is surrounded by a large mass of common brickwork, to retain the heat." [5]

The plan for Loudon's "Oven for Green Wood" is reproduced in Figure 5. The description of this oven as given by Loudon is as follows:

Oven for Green Wood. Fig. 1367 [see Figure 5] is a ground plan of a common country oven, in which a is the floor of the oven; b, the sill of the door; and c c, holes in the floor, communicating with a tunnel below, for the purpose of admitting air to urge combustion, when green wood is burned. Fig. 1368 is a longitudinal section on the line A B, in which d is one of the openings for the introduction of fresh air to the green fuel, but which is closed by a fire-brick, or by building up the entrance to the funnel, b [sic, h?], when dry fuel is used; e is a flue from the highest part of the arch of the oven, for conveying away the smoke to the chimney, g, when green fuel is used, but which is closed by a stopper at i, when the oven is heated by dry fuel; f is the door to the oven, and g the chimney. When dry fuel is used, the orifices at d and i are closed, and the fuel, being introduced at f, is ignited there, and pushed forward to the centre of the oven, where it burns till consumed, or till the oven is sufficiently heated; the smoke passing out by the upper part of f, and ascending the chimney, g. When sufficient heat has been obtained, which is between 250° and 300°, and which the baker knows by experience, never using a thermometer, the floor of the oven is cleaned out, and the bread introduced; the door, f, and the stopper, i, are then closed for a short period; after which a very small opening is made, by loosening the stopper, i, to admit the escape of the vapour exhaled from the bread. This vapour, or whatever proceeds from the door, f, when it is opened either to examine or to take out the bread, ascends by the open chimney, g. Fig. 1365 is a transvers section on the line C D; and fig. 1366 is a front elevation, showing the door to the oven, k, and the opening to the tunnel below, l. Ovens of this description are in general use in France; but in those of Paris, where dry wood is always used, the funnels, d and e, are seldom made use of, but to cool the oven, or to admit of the escape of the vapour from the bread. It may be observed, also, that, in some of the ovens of Paris, the fuel, instead of being burned on the general surface of the hearth, is consumed in iron gratings or baskets, placed over the openings, c c, whic: is found a more rapid and economical mode of heating, than that of making a fire on the floor of the oven. [6]

diagram
Figure 5. Design for an English "common country oven" for green wood, c. 1830-1860. (From J. C. Loudon, Cottage, Farm, and Villa Architecture, 721.)

Several features of Loudon's oven appear to require comment. First, it will be noted that the main flue or chimney is situated in front of the oven door. Second, flue ei and air holes c c (d) were to be closed off when dry fuel was burned; therefore these orifices were undoubtedly absent in many older ovens for which the fuel was routinely dried before use. [7] Third, the arch or "tunnel" (l) under the oven serves in Loudon's example as a part of the draft system; but as shall be seen by other plans presented in this chapter, the arch quite frequently had no function other than to strengthen the oven structure, save materials, and serve as a place for drying fuel. Many ovens had no such arches at all.


A French bake oven, c. 1760

Denis Diderot's great Encyclopédie contains a description of commercial baking as it was conducted in France about the middle of the eighteenth century. One of the magnificent plates gives a plan of a typical French bake oven of that period. [8] It is reproduced in Figure 7.

English bake oven
Figure 6. An English bake oven, c. 1847. This apparently somewhat generalized drawing seems to indicate that the chimney opening in this oven was inside the oven door. (From an unidentified clipping in a scrapbook at the Museum of English Rural Life, University of Reading, England, through the courtesy of Mr. J. A. Creasey, Assistant Keeper.)

It will be noted that the chimney in this French oven is placed outside the oven door and that there is no flue connecting the baking chamber and the chimney. Also, there are no air holes-leading from the arch under the oven to the baking chamber.

diagram
Figure 7. Diagram of a typical French bake oven, c. 1760. The letters ABCD outline the oven opening. The line FE indicates an iron plate for closing the oven mouth. The letters GH mark the hood, while M indicates the chimney. (From Diderot, Encyclopédie, I, section on "Boulanger," figures 1 and 2.)

The oven door shown in the diagram is a sheet-iron plate which drops down. Other French ovens, however, had side-opening iron doors quite similar to those generally found on British ovens. Such a door, also pictured in Diderot, is shown, with typical hinge pins, in Figure 8.

French bake oven door
Figure 8. French bake oven door, c. 1760, with typical hinge pins for seating in mortar. (From Diderot, Encyclopédie, V, section on "Serrurier," Plate VIII.)


Wood-burning oven recommended by the Subsistence Department.

U. S. Army, 1864

A manual, Bread and Bread Making, published in Washington, D. C., in 1864 for the use of army subsistence officers, contained plans and specifications for a wood-burning bake oven which was said to "have been advantageously used" for baking bread by the Subsistence Department. By 1882, when the same plan appeared in another handbook issued by the Commissary General of Subsistence, this type of oven was described as an "old style wood burning oven." [9] A National Park Service historian and an architect who studied the 1876 bakery at Fort Laramie National Historic Site in 1969 were unable to determine how extensively the plans for this type of wood-burning oven were actually employed by the army. "No plans actually showing such an oven constructed at an army post were found," they reported. [10]

Perhaps, like Loudon's oven, this one represented an ideal which was seldom realized in fact. But the plans are among the few available for nineteenth century wood-burning ovens, and they are therefore reproduced here in Figure 9.

drawings
Figure 9. Drawings of wood-burning oven recommended for use by the U. S. Army, 1864. (From Bread and Bread Making [Washington, D. C., 1864], 25-26.)

The dimensions and other specifications for the oven pictured in Figure 9 are as follows:

Foundation (g) of brick, or rubble stone masonry, depth 18 inches.

Body of Oven, (a) Length in clear12 feet.
Width in clear9 ft. 4 in.
Height from hearth to crown (in centre)23 inches.
Height at sides and back11 inches.

Arch underneath Oven, (c) Width span8 ft. 5 in.
Height at centre3 ft. 8 in.
Height from hearth18 inches.
Length from front to rear14 feet.

Arched entrance to Oven In front, i.e.Width5 feet.
  flush withHeight at centre2 ft. 6 in.
  front faceHeight at sides18 inches.
In rear, i.e.Width2 ft. 8 in.
  flush withHeight at centre18 inches.
  Oven doorHeight at sides14 inches.

Main flue, (d)14 in. x 14 in.
Back flue, (e)9 in. x 5 in.
Smoke flue, (f)14 in. x 4-1/2 in.
Distance from front of main flue to Oven door4 inches.
Distance from back of back flue to back wall 2 feet.
Distance from back of smoke flue to Oven door2 inches.
Oven door, (b), cast iron2 feet wide x 14 inches high.
Hearth of Oven above floor3 ft. 4 in.
Height of mass of masonry above foundation6 ft. 8 in.
Distance from front to rear of same15 ft. 6 in.
Thickness of side and back walls18 inches.
Thickness of division wall between two adjacent Ovens14 inches.
Maximum thickness of front wall27 inches.
Chimney, exterior dimensions2 feet 7 inches x 22 inches.
The height of the chimney to be regulated by circumstances, such as draft, nature of roof, &c., &c.
Dimensions of brick used
8-1/2 x 4-1/2 x 2-1/4

In case the bricks employed are of different dimensions from the above the necessary allowance must be made. [11]

For a single oven of the size indicated, 13,716 bricks, 14 barrels of lime, and 210 bushels of sand would be required. For two adjoining and united ovens the materials needed would be 23,848 bricks, 24 barrels of lime, and 360 bushels of sand. These estimates include "a brick hearth for each Oven." It was recommended that fire brick be used wherever there was contact with flame, though common brick could be used in such situations but would last only two or three years. Ordinary mortar was considered best for use in ovens except where it would be touched by fire. In such locations fire-clay was recommended. [12]

Concerning means of reinforcing this type of oven, the anonymous author of Bread and Bread Making had the following to say: "Both wood and coal ovens require additional strengthening. Abutments of masonry, and other means, have been employed. The best method, perhaps, is by passing ties of wrought iron through the masonry, transversely, and from front to rear . . . . If round, they should be at least 7/8 in. in diameter, if rectangular, about 1-1/2 in. x 5/8 in. Between the washers and the masonry, on each end, pieces of scantling or timber, about 4 in. thick, should be introduced. The expansion caused by heat will affect the oven to such an extent as to require frequent attention to these ties." [13]

It was advised that "great precaution" be taken to have the oven arch of the proper height. If the arch was too high the bread would be baked too much on the bottom while the top would be unbaked. When making this arch, the first six courses of brick from the side walls should be laid in mortar. The remainder of the arch should be laid dry and the interstices filled in with grouting of mortar or cement. The arch was laid, of course, over a removable frame. [14]

The author of the pamphlet admitted that objections had been made to the back flue in the wood oven on the grounds that it allowed too much hot air to escape. Such losses would not occur, he claimed, if all flues were tightly closed by dampers when the oven reached proper temperature and the fire was withdrawn. The rear flue permitted a more even distribution of the heat, he claimed. [15]

The arch under the oven was "desirable" if the ground upon which the oven was built was "wanting in firmness or solidity," but there were certain unspecified objections to this lower arch. At any rate, this arch was considered to be a convenient place for drying wood or for the temporary storage of ashes. [16]

When Major George Bell prepared his manual, Notes on Bread Making, for the Commissary General of Subsistence in 1882, he supplied more details concerning mortar, fire clay, bricks, and other technical matters. The formulas for mixing the various types of mortars and groutings are not repeated here because they surely were not those employed by Hudson's Bay Company artisans on the Columbia and because they are easily available to National Park Service personnel in Appendix No. 2 to Sheire and Pope, Historic Structures Report, Part II, The 1876 Bakery, HB#10. Fort Laramie National Historic Site. A complete copy of Bell's pamphlet is in the Fort Laramie Research File, Office of Archeology and Historic Preservation, Washington.

But one or two of the more general bits of information contained in Bell's booklet merit particular note. First, his diagrams of ovens show pavement in front of them at the bakery floor level. In view of the fact that hot embers frequently fell from the oven doors as the ashes were being removed, it would seem that such an area of brick, tile, or stone must have been a necessity in bakeries with wooden floors. Or perhaps, as the Hudson's Bay Company did with its stoves, a protective sheet of metal was placed before the ovens. Second, the ovens shown in Bell's diagrams were not composed of solid masonry as were those in the 1864 pamphlet. Rather, sand was used as filling material both over the baking chamber and beneath it (between the bottom of the oven floor and the top of the archway under the oven). [17]

As a result of studying Bell's plans as well as a number of drawings of military ovens of the latter half of the nineteenth century, National Park Service Historian James Sheire and Architect Charles S. Pope concluded that at that time "period oven design almost always located the flue [chimney] at the front of the ovens." The hot air from the fire circulated around the oven, front to back and back to front and out the flue. [18] This finding seems to confirm the view that ovens such as those advocated by Loudon, by the 1864 manual, and by Bell, with their multiple flues, were somewhat more complex than those in general use, particularly in frontier situations.


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