A privy ventilated in the manner before described is shown in figure 10.
The cowl, however, is open on four sides instead of two sides as shown
in figures 8 and 9. The working drawings (fig. 8 and 9) show that the
construction of a privy of the kind is not difficult. Figure 11 gives
three suggestions whereby a privy may be conveniently located and the
approach screened or partially hidden by latticework, vines, or shrubbery.
=Vault type.=--A primitive and yet serviceable three-seat dry-earth privy
of the vault type is shown in figure 12. This privy was constructed in
1817 upon a farm at Westboro, Mass. The vault, made of bricks, was 6 feet
long by 5 feet wide, and the bottom was 1 foot below the surface of the
ground. The brickwork was laid in mortar, and the part below the ground
surface was plastered on the inside. The outside of the vault was exposed
to light and air on all four sides. Across the long side of the vault
in the rear was a door swinging upward through which the night soil was
removed two or three times a year, usually in the spring, summer, and
fall, and hauled to a near-by field, where it was deposited in a furrow,
just ahead of the plow.
Especial attention is called to the shallowness of the vault and the
lightened labor of cleaning it out. The swinging door at the rear
facilitated the sprinkling of dry soil or ashes over the contents of the
vault, thus avoiding the necessity of carrying dirt and dust into the
building and dust settling upon the seat. This privy was in use for nearly
100 years without renewal or repairs. When last seen the original seat,
which always was kept painted, showed no signs of decay. Modern methods
would call for a concrete vault of guaranteed water-tightness,[3] proper
ventilation and screening, and hinging the seat.
[3] Directions for mixing and placing concrete to secure water-tightness
are contained in an article entitled "Securing a dry cellar," U. S.
Department of Agriculture Yearbook, 1919; published also as Yearbook
Separate No. 824, and obtainable for 10 cents from the Superintendent of
Documents, Government Printing Office, Washington, D. C.
[Illustration: Fig. 11.--Screening the approach to a privy. _A_, Raised
platform with lattice sides, suitable for short distances, convenient
and easily cleared of snow; _B_, walk hidden by lattice work; _C_, walk
enclosed by an arbor.]
[Illustration: Fig. 12.--A primitive vault privy in Massachusetts. Note
the tight, shallow, easily cleaned vault. _A_, Brick vault 5 by 6 feet,
bottom about 1 foot in the ground; _B_, water-tight plastering; _C_,
rowlock course of brick; _D_, door hinged at top; _E_, door button; _F_,
three-pane window hinged at top; _G_, passageway.]
Working drawings for a very convenient well-built two-seat vault privy
are reproduced in figures 13 and 14. The essential features are shown in
sufficient detail to require little explanation. With concrete mixtures of
1:2:3 (1 volume cement, 2 volumes sand, 3 volumes stone) for the vault and
1:2:4 for the posts there will be required a total of about 2 cubic yards
of concrete, taking 3-1/2 barrels of cement, 1 cubic yard of sand, and
1-1/2 cubic yards of broken stone or screened gravel. The stone or gravel
should not exceed 1 inch in diameter, except that a few cobblestones may
be embedded where the vault wall is thickest, thus effecting a slight
saving of materials.