Gf. H. F. Nuttall 
440 
inconvenience, for the braziers being removed and the doors opened, 
the chamber could be entered after the lapse of 1 minute. 
Capacity and Consumption of Fuel. The larger hut is capable of 
dealing with the clothing of 50 men and 100 blankets at a time. 
Captain Orr compares the fuel consumption as follows: 
Coal consumed 
by Thresh 
Foden-Lorry 
Coke 
consumed by 
two braziers 
110 lbs. To start the machine or brazier ... 150 lbs. 
70 lbs. Subsequent consumption joer hr. 
0 for 12 hrs. 
Jacobs ’ liot-air hut (Model D). This model was inadequately de¬ 
scribed by Captain Jacobs (n. 1918, p. 233) and I am indebted to Colonel 
Beveridge, R.A.M.C., for some further particulars concerning it. The 
chamber measures 15 x 15 x 7 ft. (high). The space between the double 
walls is filled with sawdust, and the floor cemented. It is heated by a 
cast iron stove having a heating surface of 1 sq. ft. per 100 cb. ft. (16 sq. 
ft. in the hut described). A perforated sheet of iron is placed above the 
stove, leaving a 3-inch space all round; it acts as a radiator. The outside 
air flows in by two pipes at the sides of the firebox, these traverse the 
combustion-chamber and deliver the now heated air into the chamber by 
openings 15 inches above floor level. After circulating in the chamber, the 
air passes down to four flues opening into the chamber but 7 inches from 
floor level and situated in the cavity of the double wall, whence it passes 
to a main exit shaft in the roof measuring 3 ft. across and twice the height 
of the building. The chamber has doors on opposite sides opening into 
corresponding rooms serving respectively for the reception and discharge 
of effects from the disinfestor. The effects are loaded on a number of 
racks which glide on wheels running on top rails on the same principle as 
in Vondran’s apparatus (Fig. 13). To avoid loss of heat, the racks are 
not all pushed in at one time but in succession, and the door is opened 
and shut as quickly as possible. The temperature in the chamber is said 
to attain 60-80° C., but Captain Orr tells me that when he saw the hut 
working last winter, the weather being cold, a temperature of 70° C. 
could not be attained. Four men are required as personnel. According 
to Jacobs the hut is capable of dealing with the effects of 80 men at a 
time, the stove burning 7-10 lbs. of coal per hour. Details are lacking 
whereby to judge of the relative efficiency and cost of building and 
running Jacobs’ hut and that of Orr, but Colonel Beveridge writes (iv. 
1918) that several of Jacobs’ huts are now in use and that they are 
efficient when properly handled. 
