operation throughout the country, varying in capacity from 
4,000 to 600,000 pounds of steam per hour 
Ladd engineers pioneered the use of large combustion 
chambers, having installed boilers in 1916 with four and 
one-half cubic feet of combustion space per rated horsepower. 
They were also the first boiler company to use heavy steel 
work for boiler settings; to suspend the drums inside the 
boiler settings; to perfect and install a patented feed box 
arrangement, special baffle tile, air tight doors and many 
other noteworthy improvements in boiler ard furnace 
construction. 
That the fundamental design of the Ladd Boiler is correct 
is proved not only by the efficient operation of these boilers 
wherever installed, but also by the fact that today several 
of the larger boiler companies have revised their original 
model to more closely conform to the Ladd design. 
Probably the largest and best known water tube boiler 
installation in the world is the eight 2,647 HP. Ladd boilers 
installed in the River Rouge Power Plant of the Ford Motor 
Company. Four of these boilers were installed in 1920, and 
at that time they were not only the largest power boilers 
ever built, but also the first boilers to be fired by a combina- 
tion of pulverized coal and blast furnace gas. The perform- 
ance of the first four boilers was so satisfactory that a 
second order for four additional boilers of the same horse- 
power capacity was placed and the hoilers installed during 
1922. 
With the rapid advances that have been made in the 
past ten years in combustion equipment and with the advent 
particularly of pulverized fuel it was logical that the largest 
company in the combustien field and the Ladd Boiler Com- 
pany should have a common interest. The progressive 
ideas of both organizations long before a consolidation was 
effected tended to bring them together in rather closer 
accord than might ordinarily be expected. On the other 
hand the engineers responsible for the design and erection of 
the Ladd Water Tube Boiler as well as the engineers of Com- 
bustion Engineering Corporation recognized that a more 
efficient piece of work could be done by having the boiler 
and the furnace practically one unit designed bv one or-