360 
Art. XIV. MISCELLANEOUS INTELLIGENCE. 
1. MecHANICAL AND GENERAL SCIENCE. 
1. Adhesion of Nails i in Wood.—Mr. Bevan has published in the 
Philosophical Magazine a series of very interesting experiments on 
the adhesion of nals when driven into different kinds of wood, the 
results of which we have abstracted and condensed as below, The 
following table exhibits the relative adhesion of nails of various 
kinds, when forced into dry Christiana deal at right angles to the 
grain of the wood: 
Number to the inches _inches forced Ibs, required 
Ib. avoirdupois. long. into the wood. to extract. 
Fine sprigs . . . 4,560. .0.44. .040. . 22 
Ditlois 0 ie By 9S} {OOK , 1OVES! 3" OAS 2 eae 
Threepenny brads . 618 . . 1.25. . 0.50. . 58 
Cast-iron nails) .  . 380. . 1.00. .050. . 72 
Sixpenny nails . . 73. . 2.50. . 100. 187 
Ditto Hee he Ss ve Penge tenets ie EOL Semaey 
Dittorrey teetewten eit radii wit. donee SO Ol yee 
Fivepenny nails . . 139. . 2.000. . 1.50. 320 
The percussive. force required to drive the common sixpenny nail 
to the depth of 14 inch into dry Christiana deal with an iron weight 
of 6,275 lbs. was ipa blows falling freely the space of 12 inches, 
and the steady pressure required to produce the same effect was 
400 lbs. 
A sixpenny nail driven one inch across the grain into dry elm 
required $27 lbs. to extract it; driven end-ways, or longitudinally, 
it required 257 lbs, for its extraction: driven end-ways two inches 
into Christiana deal it was drawn by a force of 257 lbs., but driven 
in one inch only in the same direction, it was extracted by 87 lbs. 
The relative adhesion therefore, when driven transversely or longitu- 
dinally, is as 100 to 78, or about 4 to 3, in dry elm; and as 100 
to 46, or as 2 to 1, in foe 
To extract a common sixpenny nail from a depth of one inch 
out of dry oak required . P ‘ : . 507 lbs. 
dry beech ” ‘ A . P santaOZ 
green sycamore . : 312 
a common screw of + of an inch diameter was found to have an 
adhesion about three times that of a sixpenny nail.—The resistance 
to entrance of a nail was found to be to that of extraction, in some 
experiments, as 6 to 5.—Phil. Mag. \xili, 168, 
