

YALE AGRICULTURAL LECTURES. 135 



They were then put alternately in pasture and lucerne during 

 the following periods, when the produce was found to be: 



Mr. Gould spoke at length of sainfoin, tares, and succory, 

 and after the conclusion of the lecture he exhibited the vari 

 ous grasses of which he had spoken, to the more zealous stu 

 dents, and gave them particular instruction in the botanical 

 analysis of the different genera and species. He urged them 

 very earnestly to make themselves experts in the botany of the 

 grasses, assuring them that this was essential to the acquisi 

 tion of a correct knowledge respecting them. And I am happy 

 to know that a large number of the students expressed them 

 selves determined to enter vigorously on the study of the 

 grasses, and forage plants of our country. 



SEVENTEENTH DAY. FEB. 20, 1860. 



This, the fourth and last week of the course, is especially de 

 voted to the subject of stock-breeding ; but Professor B. SILLI- 

 MAX, Jr., gave us this morning a lecture on Meteorology, 

 devoting the hour to a very simple and elementary discussion 

 of the phenomena of the atmosphere as respects the fall of rain 

 and the distribution of temperature, describing the thermome 

 ter, hygrometer, and rain-gauge. 



He spoke briefly of climates, and seasons, and the influence 

 of the sun, not only in causing the differences of seasons, but 

 on the mean daily temperature. The mean daily temperature 

 at Philadelphia had been found to be one degree above the 

 temperature at 9 A. M. The average annual temperature of 

 the atmosphere diminishes from the equator towards the poles. 



