54 



minimum thermometer and rain guage ; and, although accidental 

 breakages of instruments caused some irregularities, observations 

 were generally kept up from the time of planting to. the time of 

 harvest. A summary of the record of each observer will be found 

 under the account of his experiment. 



Each out-lying experiment was visited one or more times by 

 my assistant or myself, and the weights and measurements were 

 generally taken by my assistant. Mr. F. O. Williams served in this 

 capacity until Sept. 1st, at which time his place was taken by Mr. 

 H. J. Field. 



Systematic measurements were taken in a number of the experi- 

 ments, with a view to the study of the effects of the several fertil- 

 izers during different stages in the growth of the crop. Such meas- 

 urements have not thus far revealed general laws of any great 

 importance ; but they have, as a rule, shown that the beneficial effects 

 of nitrate of soda persist throughout the season. Only a few of such 

 measurements, to illustrate this point, are published under the 

 appropriate experiments in this report. 



A few general explanations are necessary to an understanding of 

 what follows. In each experiment, the weight of the product of 

 each plot was taken ; in experiments with oats of the straw and grain 

 separately ; with potatoes two grades were made, large and small or 

 merchantable and unmerchantable, anything as large as an average 

 hen's egg being included in the first class ; with corn, the weights of 

 hard and soft corn and of stover were separately taken. In convert- 

 ing into bushels, 32 pounds of oats, 60 pounds of potatoes and 75 

 pounds of hard corn on the ear are considered equal to one bushel. 

 In obtaining the value of the crops, oats are estimated at fifty cents 

 per bushel ; oat straw, at eight dollars per ton ; large potatoes, at 

 fifty cents per bushel ; small potatoes, at fifteen cents and hard corn 

 at sixty-five cents. 



The cost only of fertilizers is taken into consideration in calculat- 

 ing gain or loss. No account is made of the labor of applying. 

 Nitrate of soda is estimated at $50 per ton ; dissolved bone-black, at 

 $30; muriate of potash, at $40 ; plaster, at $9 ; lime, at $12 and 

 barn-yard manure, at $5 per cord. 



In determining gain or loss from any plot it is compared with the 

 two nearest nothings, each being given a weight inversely propor- 

 tional to its distance from the plot under comparison. 



In the determination of the effect of each of the^ingredients of 



