180 Agricultural Experiment Station, Ithaca, N. Y. 



of tke riser with comparatively little loss and be distributed 

 throughout the returns to be given off where it is most needi^; 

 and the steam gives us a greater uniformity of temperature 

 throughout the houses, as is well shown in Table III. 



The following table shows the extreme variations in the differ- 

 ence of temperature at the opposite ends of the houses at any 

 one time, disregarding the mornings before mentioned; also the 

 extreme fluctuation at each point, during the whole time: 



TABLE III — Fluctuation. 



Fluctuation in difference between thermometers riser E and F. 

 Twelve less to 22 more, or 34 degrees (average difference 13 

 degrees). 



Fluctuation in difference betT\^een risers C and D, 1 to 10, or 9 

 degrees (average difference, 4 degrees). 



Fluctuation between risers A and B, 2 to 15, or 13 degrees (aver- 

 age difference 10 degrees). 



Fluctuation in riser A, during test 189 to 203,or 14 degrees. 



Fluctuation in riser without pressure 189 to 195, or 6 degrees. 



Fluctuation in riser B, during test 180 to 192, or 12 degrees. 



Fluctuation in riser C, during test 180 to 205, or 25 degi-eesi 



Fluctuation in riser D, during test 179 to 202, or 23 degrees. 



Fluctuation in riser E, during test 105 to 180, or 75 degrees. 



Fluctuation in riser F, during test 79 to 1G4, or 85 degrees. 



It ia seen that while the riser at the west end of the hot water 

 house, E, averaged 13 degrees higher than the one at the east end 

 F, it was in one case 12 degrees lower and the extreme difference 

 in the opposite direction was 22 degrees, or a fluctuation of 34 

 degrees, whUe that between opposite ends of the steam-houses is 

 much less, being only 4 degrees in the warm-houses, C and D. 

 Another surprising point is the great variation in tempei'ature at a 

 given point in the hot-water riser, averaging over four times as 

 great as that of steam. Of course, the steam temperatures, if 

 taJien in the middle of sunny days, or at any time when there was 

 little or no circulation, would show a greater divei-sity than this, 

 but it is to be borne in mind that these are just the times when the 



