OBSERVATIONS UPON THE PHENOMENA OF PLANT-LIFE. 335 



innumerable broken twigs. I then remembered that a day or two before there 

 had been a storm of sleet and rain, which had encased the trees with a heavy 

 coating of ice, and following that a violent wind, which had twisted and broken 

 many of the smaller branches. From these was now flowing a brilliant shower , 

 of sap, sparkling in the bright sunshine. I could not perceive that this whole- 

 sale tapping diminished at all the flow from the trunk, or in any manner in- 

 jured the tree." 



ICICLES 



of frozen sap are not unfrequently seen depending from the branches of maple 

 and bntternut trees during severe cold weather, when the temperature rises 

 only slightly above 33*^ F. at mid-day. On Thanksgiving Day, 1874, the ther- 

 mometer, in the shade, indicated 33*? F. at 2 P. M. A sugar maple was tapped 

 at the ground, and fifty feet above it, and while there was no flow from the 

 lower orifice, the upper one bled four drops per minute. 



EXPERIMENTS WITH THE SUGAR MAPLE. 



On the twentieth of November last the weather was cold, and at 11 A. M. 

 there was a rapid fall of soft snow, followed by a rising temperature. At half-past 

 twelve P. M. the mercurial gauge in the top of a sugar maple indicated a 

 pressure of about nine feet of water, while a gauge at the ground showed neither 

 pressure nor suction. 



In the case of a tree tapped in 1873, on the north and south sides, in order 

 to compare the flow from each, it was found that, for some reason, the north 

 spout yielded nearly twice as much sap as the south one, and flowed two weeks 

 longer. It appears probable that this was an exceptional instance, and possi- 

 bly to be accounted for by the fact that the roots of the south side ran under 

 a highway, while those of the north side luxuriated in a rich meadow. 



In 1874 another tree about sixty feet in hight and four feet and ten inches 

 in girth was subjected to the same trial. The total flow from the south side 

 was eighty-six pounds and four ounces, while that from the north side was 

 sixty-eight pounds and five ounces. Near the close of the season only did the 

 flow from the latter exceed that from the former. There can be no doubt that 

 it is much wiser to tap all sugar trees on the south side, because the sap will 

 flow earlier and more abundantly than from the shaded side, while the late sap 

 is of little value to the sugar-maker. 



Another sugar maple, seventy feet high and four feet in circumference, was 

 tapped on the south side in five places, the holes being two feet apart on a 

 vertical line, so that spout number one was near the ground, number two di- 

 rectly above number one, number three two feet above number two, and so on. 

 During the month of April the sap from each spout was weighed daily, and 

 the results were as follows, viz.: The total flow was one hundred and twenty 

 pounds and one ounce. From number one, near the ground, was collected 

 ssventy-eight pounds and ten ounces; from number two, twelve pounds and 

 two ounces j from number three, five pounds and ten ounces; from number 

 four, eight pounds and seven ounces ; and from number five, fifteen pounds 

 and four ounces. These facts are, in the main, what would be expected from 

 the other observations made concerning the flow of maple sap. 



The eflect of increasing the number of spouts inserted into a tree was tried 

 on two red maples, which flow much less than the sugar maple and for a shorter 

 time. Ten spouts in one tree, sixty feet high and four feet eight inches in 

 girth, were found to flow, during the first half of April, seventy-eight pounds 



