34 OPERATIONS OF FUEL-TESTING PLANT IN 1905. 
Considering the facts that the floor of the combustion chamber had no special rigidity and 
that this was our first experience in selecting material for and erecting such a structure, it is 
fair to assume that it is commercially practicable to use such mixing structures in combus- 
tion chambers. 
The object of this construction is to subdivide and mix the gases coming from the fuel bed 
and to cause them to travel a greater distance before striking the cold tubes. These fire- 
clay masses also absorb heat between firings and give it out just after firings when there is a 
large rush of cold air and hydrocarbons. 
Recently the lowest row of tubes of boiler No. 2 has had the protecting tiles changed from 
the "C" to the rectangular flat-bottomed type. The "C" tiles gave much trouble from 
breakage due to radiant heat and were also frequently broken with fire tools. The flat- 
bottomed tiles are more durable and will be put on the other boiler as soon as its "C" tiles 
need replacing. The rectangular tiles weigh about the same as the "C" tiles. 
On measurement of the areas left between the tubes at the end of the lower and upper 
baffles where the gases respectively enter and leave the boiler tubes, it was found that a 
much shorter length of openings would do, so more tube tiles were added below and more 
iron tiles above until the openings were each reduced nearly one-half; thus forcing the gases 
to travel a slightly greater length of tube surface. 
The following new instruments have been added since the tests of last year: One Crosby 
recording steam gage, one Bristol recording draft gage, one Bristol recording flue thermome- 
ter, one Wanner optical pyrometer. 
The instruments have served as a check on the regular observations. They have been 
checked with the other instruments used for the same readings. The optical pyrometer 
used for reading combustion-chamber temperatures has been easily handled and has 
been found exceedingly useful in this work. 
These modifications of the equipment have perhaps improved the over-all efficiencies of 
this year's (1905) tests 2 or 3 per cent over last year's. 
PERSONNEL. 
Prof. Dwight T. Randall, who had local charge of the steaming tests in 1901, returned to 
the University of Illinois, and Mr. Walter T. Ray, of the Chicago Edison Company, was 
appointed to the vacancy. Later Mr. Clyde McClure resigned as boiler-room chemist, to 
assume duties with the above company, and was replaced by Mr. Ralph Gait, of the Univer- 
sity of Michigan. The same fireman, Mr. Henry Arens, has been employed continuously 
since the tests began. Mr. Robert H. Kuss, until recently instructor on steam boilers at the 
University of Illinois, has joined our local staff, as have Messrs. Lloyd R. Stowe, W. M. Park, 
Fred E. Pahmeyer, and R. C. Matthews. The following men have also been with the work 
from the start: Messrs. Henry Kreisinger, H. W. Weeks, R. IT. Post, and C. II. Green. 
CHANGES IN METHODS OE TESTING. 
The only important change introduced in test procedure consisted in making three trials 
with each coal, but the three ran so nearly alike that hereafter only two will be made. In 
the first series only one trial was made with each coal. The feeling has been that some 
changes in proportions of baffling might increase the over-all efficiency of all the trials. 
Still the temptation to make any marked changes has been resisted, in the belief that the 
object for which these tests are being conducted will be better served by keeping to the same 
ratios in all the tests. The results will then more truly show the comparative value of the 
various fuels than they would if changes in the setting were attempted. 
WORK DONE. 
On 64 coals, some of them washed in part, there were made 185 tests, which are included in 
this report; several tests were thrown out. Coals were tested from Illinois, Indiana, Ken- 
tucky, Maryland, North Dakota, Ohio, Pennsylvania, Virginia, West Virginia, and Wyoming. 
