275 
H. Orr 
two feet at the other side, rendering an even distribution of heat impossible. 
It was evident that these errors were due to carelessness in construction, and 
not to any faults in the drawings. Although several of the other disinfestors 
examined had been erected by unskilled labour, they were built according 
to specification, and were working efficiently. 
Temperature measurements were made on thirty different occasions, these 
tests being distributed over six disinfestors. In 28 cases out of thirty, the 
temperature reached in the garments was sufficient to destroy any lice and 
their eggs. The failure of the other two charges was to be expected before 
the beginning of the experiments, as the working instructions were not being 
observed. In both cases there was only a thin layer of coke at the bottom 
of the braziers, and a sufficient supply of hot air could not be maintained. 
One of these tests was carried out in the badly constructed disinfestor referred 
to above, in which the rails entered obliquely, and in which the heat distribu¬ 
tion was unsatisfactory. Even in these adverse circumstances, lice were 
killed in the clothing, but doubt remained as to the destruction of the nits. 
In chambers constructed according to specification, and worked in accordance 
with instructions, the results were invariably good. 
With the thermo-couple employed, the temperature at any point in the 
clothing, and in any region of the chambers could be observed continuously 
from the beginning to the end of the process of disinfestation. 
The following are details of measurements carried out at four of the 
disinfestors: 
Test A. Surprise visit to disinfestor at Gouy Servins at 12.30 p.m. on 
13.vii.18. 
The attendants had stopped work for dinner. 
The braziers had not been touched since 8 a.m., and were half-full of 
coke. 
A truck was loaded with shirts, one shirt on each peg. 
The point of the thermo-couple was placed in the folds of a shirt. 
In 1 minute the temperature had reached 54° C. 
In 5 minutes 
67 
In 10 ,, 
75 
In 15 ,, 
>> 
81 
In 20 ,, 
85 
All lice were shrivelled, also nits. 
Test B. Surprise visit to bath house at Neuville St Vaast, at 11.25 a.m. 
on 14.vii.18. 
Bathing was in operation, men were arriving in parties of 50 every half- 
hour. All men were bathed, issued with clean clothing, and were compelled 
to have their service dress passed through the disinfestor. The wire of the 
