UTAH ACADEMY OF SCIENCES 233 
«“The modern Scotch retorts are all of one general 
type, the main points of difference between those used 
in different plants being in the shape of the cross section 
of the retort and the means used for discharging the spent 
shale from the bottom of the retorts. Time will not 
permit a complete description of the Scotch retorts, but 
briefly, they are vertical and consist in descending order, 
of a (1) fresh shale hopper attached to a (2) cast iron 
retort, which is fourteen feet high, and tapered, being 
smaller at the top than the bottom. At the juncture of 
the hopper and the iron retort a vapor discharge line, 
protected by a lip to prevent its being clogged with shale, 
leads to the vapor main. The iron retort is usually round 
or oval in cross-section and is, if round, two feet in diam- 
eter at the top and two feet four inches at the bottom. At 
the bottom of the iron part of the retort it is joined to 
a (3) brick part, also vertical and tapered, and made of 
a single tier of specially shaped fire brick. The joint 
between the iron and brick parts of the retort is made of 
a special kind of fire clay, and in operation considerable 
care must be exercised in firing, to prevent the joint from 
pulling apart or cracking. The brick part of the retort 
may be rectangular or round in cross section. If round, 
the diameter at the bottom is about three feet; usually 
the height of the brick part is about twenty feet. 
‘Below the brick part, and attached to it, is the (4) 
spent shale discharge mechanism, which differs in differ- 
ent types of retorts. In one type of retort the discharge 
apparatus is either a pair of toothed cast iron rolls, which 
rotate slowly towards each other and drag the spent shale 
from the retort. The discharge mechanism in a more com- 
monly used retort, consists of a flat iron plate, on which 
the shale column in the retort rests, while a curved arm 
moves slowly over the plate and forces the spent shale 
from the plate as the arm rotates. The arm is operated 
by a shaft passing through the plate and actuated by a 
system of ratchets and pawls, as are also the other types 
of discharge mechanisms, the motion of the lever arms 
4Garvin, Martin J., The Past, Present and Future of the Oil- 
Shale Industry: Unpublished manuscript to appear in an early issue 
of California Oil World. 
