"Although a shale to steam ratio of 5 to 1 had been planned for this run, it more nearly approached 7 to 1 because of faulty operation of the feeder. Steam flow during the shale feeding period averaged 60 lb. hr. A 5-minute purge period at a rate of approximately 147 lb. of steam per hour was used after shale feeding stopped to clean out retort and process lines. This increased the average steam flow for the entire run to 61. 1 lb. per hour. The shale feed rate averaged 429 lb. per hour for the run. This is equivalent to a throughput of 6920 lb. per(hour) (sq. ft.). Calculating log mean stream velocity in the retort tubes was 17.8 ft./sec.; calculated shale velocity. 8.4 fL/sec.; and calculated shale retention time. 6 sec. Table 2 shows the temperatures which were recorded just prior to stating the shale charge but with steam flowing through the system, and again after shale feeding had started. Figures 1 and 2 show the temperature histories recorded during the run, figure 3 the steam flow, and figure 4 the temperature of the steam as it enters the retort."