PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 479 



He aunouncecl in conclusion that a very perfect meridian circle 

 has been ordered for the Observatory from Germany. 



Prof. Hough of the Dudley Observatory, described the beautiful 

 self-recording barometer invented by him, and first exhibited in 

 public at the last fair of the American institute, a full description 

 of which will be found in the Transactions of the Institute for 

 1865-6. 



The description of this instrument elicited considerable discus- 

 sion, from which it was evident that some of the savans present 

 had not appreciated the importance of Prof. Hough's improve- 

 ments, and did not foresee the entire revolution which must soon 

 occur in the method of making meteorological observations. 



Dr. L. Bradley, of Jersey City, read papers on "The Anthistome- 

 ter," "The electro-magnet" and "The galvanic battery," all of which 

 had in substance been previously presented before this Association. 



The new chemical nomenclature, first explained by rae before 

 this Association in May last, was also the subject of a long paper. 



One or two other novelties were presented, which I had no 

 opportunity of examining. 



The effect of water, in modifying the temperature of the air, is 

 set forth in the following summary: 



The Fruit-Producing Belt of Michigan. By Professor A. 



WiNCHELL. 



This paper was an exposition of the influence of Lake Michigan 

 upon the climate of the belt of country lying along its eastern 

 shore, and extending about forty miles inland, and embraced a 

 statement of the efiect which this influence has upon the agricul- 

 tural and horticultural adaptations and capabilities of that region. 

 Lake Michigan is a body of water 350 miles long, 75 miles broad 

 and 900 feet deep. This enormous mass of water never attains 

 an elevation of temperature greater than 45 or 50 degrees, and 

 never sinks below 35 or 40 degrees. It consequently exerts a 

 poAverful influence in moderating the rigor of both winter and 

 summer. Since our prevailing winds are from the west, this 

 influence is principally felt upon the Michigan shore. 



In order to determine definitely the extent of this influence 

 comparisons have been made by Prof. Winchell, betAveen the 

 results of meteorological observations kept on the eastern shore 

 of the lake, and at various other localities in the same latitude 

 from Maine to Minnesota. These comparisons show that the mean 



