Today in 1901, US Patent 672819 A was issued, an invention of Alfred Blackie, for his “Apparatus For Drying Hops.” There’s no Abstract, and it takes a lot to explain everything, but essentially it’s a “kiln having an open sparred floor and a number of portable hop-receptacles having porous bottoms and tops, whereby currents of heated air may be passed through said floor and through said receptacles containing the hops for drying them.” But that’s pretty simplified, here’e more:

The present invention is illustrated in the accompanying drawings, in which Figure 1 is a plan view of the floor of a round kiln suitably prepared to receive the frames containing the hops to be dried, and Fig. 2 is a similar view showing such floor with the frames in position thereon. Fig. 3 is a perspective view showing one method of manipulating the frames. Fig. 4 shows a number of the frames as arranged on the cooling-floor after drying when it is desired to cool the hops quickly; and Fig. 5 showsthe manner of arranging such frames when the cooling is to take place more gradually. Fig. 6 is a plan view of a square kiln with frames suitably arranged thereon, and Fig. 7 shows an arrangement which may be used in connection therewith for manipulating the frames. Fig. 8 shows a modification of such arrangement. Fig. 9 is a sectional view showing one method of attaching the lids or covers of the frames in position, and Fig. 10 illustrates a modified arrangement for the same purpose. Fig. 11 is a plan view, and Fig. 12 a transverse section illustrating the method I prefer to employ for attaching the porous cloth or other suitable material to the lids or covers and bottoms of the frames.

This apparatus comprises an oast-house or kiln of any suitable form provided with an ordinary sparred floor 1, composed of slats or spars disposed apart from each other, leaving open spaces between them for the passage of air, and hop receptacles or frames 4, having porous tops and bottoms, disposed on said floor. When the hop-receptacles are placed directly on the floor, portions of the heated air for drying the hops rise through the floor between the receptacles and around the ends thereof and have no effect upon the hops and the heat is consequently wasted. To avoid this waste of heat, intermediate strips 2 of wood or other suitable material, together with similar end strips 2 and 2 are disposed on the floor 1 in such manner as to form completely-walled enclosures or compartments approximating in shape the hop-receptacles. The intermediate strips 2 are arranged in such position that they come immediately below the joints in the hop-receptacles 4 when the latter are placed in position in the kiln, and the end strips 2 close the end spaces under the outer ends of said receptacles adjacent to the inside wall of the cast-house or kiln and the strips 2 close the spaces under the inner ends of the receptacles, so as to prevent the escape of air around the frames. By this means the heated air will pass upward through the hop-receptacles only, and consequently the Whole thereof will be utilized in drying the hops, as the whole floorspace, except the parts beneath the porous hop-receptacles, is entirely closed or sealed. The strips referred to may be covered with felt, if desired. It continues from there.