172 Agricultural Experiment Station, Ithaca, IN". Y. 



These tables show that with tliis small plant, the hot water circula- 

 tion began almost at once after the fire was started, but required 

 nearly two hours to reach a point where it would give off much per- 

 ceptible heat to the house. With steam, on the other hand, no effect 

 was shown in the pipes thirty minutes after the fire was started, but in 

 forty minutes they were all giving off heat at their ordinary capacity. 

 While hot water moved off first, steam reached the goal the quicker. 



Influence of length of pipe. — By taking the averages for the final 

 test under each method, with the long run added, (see pages 164, 165), 

 it was found that in passing through some 84 feet of pipe to the 

 further end of this run, the hot water lost 54 8-13 degrees of heat 

 while the steam lost 7 1-15 degrees, showing that the distance to be 

 traversed is a much more important consideration with hot water than 

 with steam. This run was put up in the way supposed to be best 

 adaj^ted to hot water circulation, namely, highest at the point farthest 

 from the boiler, and it had an abundant fall. 



Conclusions. 



Under the present conditions, which, as previously stated, Avere 

 strongly in favor of hot water, the following results can be deduced. 

 It will be observed that they confirm several of the conclusions of 

 last year. 



1. Hot water maintained a slightly greater average difference 

 between the minimum inside and outside night temperature than steam. ' 



2. There was practically no difference in the coal consumption 

 under the two systems. 



3. With a small plant like this, the fluctuations under both sys- 

 tems are much greater than in larger ones, and neither proved very 

 satisfactor3\ 



4. The utility of slight pressure in enabling steam to overcome 

 unfavorable conditions is fully demonstrated. 



5. The addition of crooks and angles is decidedly disadvan- 

 tageous to the circulation of hot water and of steam without pres- 

 sure, but the effect is scarcely perceptible with steam under low pressure, 



6. In starting a new fire with cold water, circulation commences 

 with hot water sooner than with steam, but it requires a much longer 

 time for the water to reach a point where the temperature of the house 

 will be materially affected, than for the steam to do so. 



7. The length of pipe to be traversed is a much more important con- 

 sideration with water than with steam. 



8. A satisfactory fall towards the boiler is of much greater impor- 

 tance with steam than the manner of placing the pipes. 



