165 
Producer of Messrs. Crossley Bros. 
the grate level already referred to. In this producer there is 
also a “secondary dry air ” supply, which, owing to a throttling 
action, reduces the proportion of steam as the load is reduced. 
A special feature of the scrubber is the layer of sawdust at 
the top, the object of which is to clean the gas from dust and 
from tar. 
FIG. 4. — Messrs. Crossley Bros., Ltd. Gas Producer and Scrubber. 
In the second plant exhibited by Messrs. Crossley the 
producer was the same as the one above described, with the 
addition of an arrangement for heating the air and the steam by 
means of the exhaust from the engine. Some heat is recovered 
in this way, but probably the greatest advantage is the improved 
possibility of regulating the amount of steam as may be 
required by variations of load. It is obvious that with such 
