294 TRANSACTIONS OP THE AMERICAN INSTITUTE. 



latter herbs,) nor any other invading plant, hence its green appearance is 

 splendid, owing to its great compactness and nniformity/ " 



Professor Mapes. — Tiiere is one remark in that paper which conveys an 

 error in regard to milk. It is not the heaviest milk which is most valuable 

 for bntter-makers, whatever it may be to those who sell it in the city. Thi» 

 has been proved in a series of experiments with the hydrometer and lac- 

 tometer. The lightest milk gave the greatest yield of cream. The more 

 watery the feed given to cows, the heavier will be the milk. 



Maple Sugar. 



Mr. Jona. Martin, Candia, N. H., sends us a beautiful "sample of rock 

 maple sugar, which we made from the sap of a tree that stan-ds in our doar- 

 yard. The sap was caught in a pine bucket^ and boiled in an iron boiler 

 over the &tove, down to sugar; there was no process of cleaning or drain- 

 ing or whitening whatever." 



Prafessor Mapes. — The secret of thia is that the sugar was boiled at 

 what is called lew proof. The same result takes place when cane sugar 

 is boiled in a vacuum. The quicker sap can be boiled and the less it ia 

 exposed to the atmosphere the better. That is what is requisite in all 

 8Ugar-boiling, great rapidity of action from the time the juice is expressed 

 until the boiling is finished. 



The Cankerworm in Iowa. 



Mr. J. H. Hilton, Batavia, Jefferson county, Iowa, sends specimens of 

 insects which are infesting their apple trees. 



Dr. Trimble. — These worms have the same characteristics, as those which 

 are now crawling up the apple trees of New England, and will produce the 

 cankerworm. The only remedy is to keep them from crawling «p,, as the 

 females have no wings. 



Black Knot. 



Mr. Levi Clark, De Peyster, St. Lawrence county, N. Y,, sends speci- 

 mens of the black knot from plum trees, which is making its appearance i» 

 that section. 



Dr. Trimble. — It is produced by an insect, but not the curcnlio. The only 

 remedy for it is excision as fast as it makes its appearance. 



Carbonized Shingles. 



Messrs. Tenny & Bennett, Hubbardston, Mass., present specimens of 

 shingles which are carbonized by passing them between red hot iron rollers, 

 which, it is said, protects them from decay. 



Professor Mapes. — These shingles will last longer than the ordinary shin- 

 gle, or even painted shingles. I understand the cost of carbonizing is about 

 cue dollar per thousand, 



A New Hay Press. 



Mr. J. D. Wilbur, Pleasant Plains, Dutchess county, N. Y., presented a 

 working model of a horizontal hay press lately invented by him. It i» 

 double acting, the hay being placed in the center and a follower constantly 

 working carries the forkfuU's back and forth to bales forming at each end. 



