1 1 8 Vegetable Staticks. 



Experiment XXXVIIL 



March 10, at the beginning of the bleed- 

 ing feafon, (which is many days fooner or 

 later, according to the coldnefs or warmth, 

 moifture or drinefs of the feafon) I then cut 

 off a branch of a tint bfcgzt b, (Fig. 20.) 

 which was 3 or 4 years old, and cemented 

 faft on it a brafs-collar, with a fcrew in it ; 

 to that I fcrewed another brafs collar, which 

 was cemented faft to the glafs tube z, 7 feet 

 long and f inch diam. (which I find to 

 be the propereft diam.) to that I fcrewed 

 others, to 38 feet height. Thefe tubes were : 

 fattened and fecured in long wooden tubes, 

 3 inches fquare, one fide of which was a 

 door opening upon hinges ; the ufe of thofe 

 wooden tubes was to preferve the glafs tubes 

 from being broke by the freezing of the fap 

 in them in the night. But when the danger 

 of hard frofts was pretty well over, as at the 

 beginning of April, then I ufually fix'd the 

 glaffes without the wooden tubes, fattening 

 them to fcaffold poles, or two long iron fpikes 

 drove into the wal£ 



Before I proceed to give an account of 

 jhe rife and fall of the fap in the tubes, I 



Tt'l I ! 



