]G4 ATTRACTION AND REPULSION 



inferred from the sap having farther to rise and descend, 

 and having- no boughs to divert or delay it, the circulation 

 must be more fine and rapid, most increase be left in the 

 neighbourhood of the boughs at the top of the tree, and 

 least on the sides at the lower part; consequently adding to 

 the length of the head, and rendering more fine each annual 

 increase to the body ; thereby producing a close-grained, 

 clean, long, and regular, easy-tapering, useful piece of tim- 

 ber ; instead of a coarse-grained, short, sudden-tapering 

 trunk, with a quantity of boughs and knots. 

 Applicable to The forgoing observations and rules are meant to apply 

 other timber, to fir timber only, but to a certain degree they may be- ap- 

 plied to other timber"; though by no means to the same ex- 

 tent, or v age. But if applied as far as the first fourteen years 

 of their growth, and then the pruning altogether omitted,' 

 and the thinning-out very much increased, any plantation 

 would be rendered much more valuable, than if left entirely 

 to nature. 



ROBERT SALMON, Surveyor, 

 Woburn, April 2, 1S06\ 



III. 



Abstract of a Memoir read at the Meeting of the fifth Class 

 of the Institute, September the 20th, 1S06, by Mr. La- 

 place, on the apparent Attraction and Repulsion of small 

 Bodies floating on the Surface of Liquids*. 



J 

 Bodies floating -*-^ tne tneov y l nave g lVen of ca pdlary attraction, I have 

 on fluids at- subjected to analysis the attraction of two vertical and pa* 

 tr.icted toward jj j , e very near each other, with their lower extre- 

 each other, i ' 



mities immersed in a fluid. I have shown, that, if they be 



when they are of the same matter, this action tends to bring them nearer 



of the same t g e ther ; whether the planes elevate the fluid near them, 



as ivory immersed in water ; or depress it, as laminar talc, 



on which we feel a kind of unctuosity, that- prevents them 



* Journal de Physiuue, Vol. LXI1I. p. 248. 



from 



