Division of Horticulture. 



S. T. MAYNARD. 



EXPERIMENTS IN HEATING GREENHOUSES. 



STEAM HEAT versus HOT WATER. 



During the past few years much attention has been given to the 

 subject of economy iu heating greenhouses, and the manufacturers 

 of steam heating apparatus have made great efforts to supplant the 

 long established system of hot water heating. 



In order to get at some facts in regard to this subject, so impor- 

 tant to the grower of plants under glass, and gain some positive 

 knowledge as to the relative value of the two systems, two houses 

 were constructed during the summer of 1888, 75x18 feet, as nearly 

 alike as possible in every particular. Two boilers of the same pat- 

 tern and make* were put in, one fitted for steam and one for hot 

 water ; the steam for heating the east house, and hot water for the 

 west and most exposed one. The boilers were completed and ready 

 for work in November and were tested until January 9th, 1889, when 

 these experiments began. 



Records of temperature of each house were made at 7-30 and 

 9 a. m., and 3, 6 and 9 p. m. Sufficient coal was weighed out each 

 morning for the day's consumption and the balance not consumed 

 deducted the next morning. The two boilers and fittings were put in 

 so as to cost the same sum and w^ere warranted to heat the rooms 

 satisfactorily in the coldest weather. 



The following tables give the maximum, minimum and average 

 daily temperatures for the months of January and February, with the 

 amount of coal consumed. The average daily outdoor temperature 

 is given in the second column for comparison. 



^. W. Foster, Manufacturer, 51 Charlestown St., Boston, Mass. 



