INTRODUCTION 



The art of forcing vegetables and flowers is not a 

 new one ; however, its economic aspect is of modem 

 origin. The Thirteenth Census of the United States 

 estimates that the total area of land under glass in 

 1909 was 114,655,000 square feet, of which 

 105,166,000 square feet were in greenhouses and 

 9,490,000 feet were covered by sashes and frames. 

 About 99% of the value of the plants and flowers 

 in 1909 was produced in 7,444 establishments, the 

 average value of each of these establishments be- 

 ing $4,630.00. As is natural to expect, these estab- 

 lishments were located near large cities. The lead- 

 ing states in value of forced flowers and plants were 

 New York with $5,110,000; Pennsylvania with 

 $3,761,000; Illinois with $3,681,000; New Jersey 

 with $2,839,000; Massachusetts with $2,432,000; 

 Ohio with $2,357,000; California with $1,374,000; 

 Indiana with $1,202,000; Michigan with $1,132,- 

 000; and Connecticut with $1,042,000. States with 

 less than a million are not here recorded. The total 

 value of forced plants and flowers as estimated for 

 1909 was $24,930,000. 



There are as yet no available figures of the area 

 and the money value of the greenhouse industry. 

 It is, however, reasonable to suppose that the num- 



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