48 JAMESTOWN CONGRESS OF HORTICULTURE 



house the necessary amount. Large boilers are required to produce 

 steam at as low a pressure as possible to heat large territories of glass, 

 that is, by the acre. The use of hot water is an ancient process to the 

 modern market gardener. When heating by steam the pipes are placed 

 3 or 4 feet above the surface of the soil at such distances apart as 

 the desired temperature requires, and only enough pipes to give the 

 highest temperature required in the coldest season. 



The moisture or water is supplied from pipes arranged similar to 

 the steam pipes and used as the crops demand. I have spoken of the 

 use of electricity in the giving of light, but we have found that it is 

 equally as beneficial when applied to the soil by means of a current 

 passing through the soil from a battery at each end of the bed and 

 connected with a wire. 



The circulation is manifest through all the soil to a marked degree. 

 The amount of this has to be tested at all points of the bed until the 

 proper amount of current is obtained, otherwise if too high the crop 

 will show a forced growth. This experiment has only just begun and 

 when we can regulate the current to that amount which is of the 

 greatest benefit without forcing the crop too much it will prove of the 

 greatest value to the modern market gardener. I have tried the experi- 

 ment in one of my houses in a bed 400 feet long, and the difference in 

 growth between that bed and one not treated was quite marked. 



Now a word about greenhouses and their construction. The 

 foundation should be of cement, the frame of iron and the purlins in 

 cold climates of wood. The glass should be as large as possible, 

 20 in. by 30 in. having been found to be the most economical. As to 

 the size of the houses, I would recommend one 20 feet wide to be 100 

 feet long; one 30 feet wide to be 200 feet long; one 40 feet wide to 

 be 300 feet long; and one 50 feet wide to be 400 feet long. These 

 proportions have proved to be the most satisfactory, but I should 

 recommend the larger size as being much more economical to heat 

 and regulate. 



I have only mentioned the way to produce crops as a whole in the 

 market garden. Each one of the crops mentioned above could easily 

 be made the subject of a lecture by itself, but I have not the time to 

 go into the matter now. This subject of the commercial culture of 

 vegetables has been studied deeply in New England and the prosperity 

 of the majority of our market gardeners shows with what success. 



There are many branches of agriculture and horticulture which 

 may be familiar to many men, but the method to-day is to intensify 

 and specialize, and the truly successful man is the one who cultivates 

 only a few crops, those to which his land and climate are best adapted 

 and those which have the greatest demand in his market. We have 

 found in New England that while we depend upon the farmers of the 

 West and South for many of the necessities, they look to us for many 

 of the finer vegetables to supply them at certain seasons of the year. 



While corn, wheat, oats and potatoes are their agricultural pro- 

 ducts, lettuce, cucumbers and celery are ours. 



