BOR 



BOR 



about one-fifth of the field, serving as a 

 difference in a coat of arms, to distin- 

 guish families of the same name, or per- 

 sons bearing the same coat. 



BORE, among engineers, denotes the 

 diameter of the barrel of a gun or cannon, 

 or rather its whole cavity. 



BORE, square, among- mechanics, a 

 square piece of well-tempered steel, fit- 

 ted into a handle, serving to widen holes, 

 ami make them perfectly round. 



BOREALIS. See the article AURORA. 



BOHELLI, (J. ALPIIO.VSO) a celeorat- 

 ed philosopher and mathematician, born 

 at Naples the 28th of January, 1608. He 

 was professor of philosophy and mathe- 

 matics in some of the most celebra ed 

 universities of Italy, particularly at Flo- 

 rence and Pisa, where he became highly 

 in favour with the princes of the house of 

 Medicis. But having been concerned in the 

 revolt of Messina, lie was obliged to retire 

 to Rome, where he spent the remainder 

 of his life, under the protection of Chris- 

 tina, Queen of Sweden, who honoured 

 him with her friendship, and, by her libe- 

 rality towards him, softened the rigour of 

 his hard fortune. He continued two years 

 in the convent of the regular clergy of 

 St. Pantaleon, called the "Pious Schools," 

 where he instructed the youth in mathe- 

 matical studies. And this study he pro- 

 secuted with great diligence for many 

 years afterwards, as appears by his cor- 

 respondence with several ingenious ma- 

 thematicians of his time, and the frequent 

 mention that has been made of him by 

 others, who have endeavoured to do jus- 

 tice to his memory. He wrote a letter to 

 Mr. John Collins, in which he discovers a 

 great desire, and endeavours to promote 

 the improvement of those sciences ; he 

 also speaks of his correspondence with, 

 and great affection for, Mr. H nry Olden- 

 burg, Secretary of the Royal Society; 

 and Dr. Wallis; and of the tiien late 

 learned Mr. Boyle. He died of a pleim- 

 sy, in his 72d year, December 31, 1679. 

 His principal work was " De Motti Ani- 

 malium," in two volumes, small 4to. The 

 object of this work was to explain the 

 functions of animal bodies, on mechani- 

 cal principles. He describes the fibres 

 of the muscles, and measures the power 

 or force which each possesses, and the 

 power of them collectively. He points 

 out in what manner that power is increas- 

 ed or diminished, bv the manner in which 

 the fleshy fibres are joined to the tendons. 

 He calculates the power of the heat, in 

 propelling the blood, which he supposes 

 equal to 180,000 pounds weight. In his 



calculations, Borelli was found to have 

 erred in many respects, but his principles 

 were gent-rally admitted. 



BOliEK, an instrument invented for the 

 purpose of searching or exploring the 

 nature of soils? it consists of iron rods, 

 about six feet long, made to screw into 

 one another ; to the lower one is fixed a 

 steel point ; with an instrument of this 

 kind, two men will easily sounrl the depth 

 of twelve feet in a quarter of an hour, if 

 they do not meet with stones. When the 

 rod becomes too heavy to be conveniently 

 manage.: with the hand, it may be raised 

 by a rope fastened atone end to the han- 

 dle, and at the other to a roller, or kind 

 of windlass, erected at a proper height, 

 perpendicularly over the hole, and turned 

 with one or two handles. The toughest 

 iron is used for making this instrument, 

 which should be well hammered, till its 

 surface is quite smooth and even ; for the 

 least roughness and inequality would oc- 

 casion a friction, that must greatly retard 

 its working. For the same reason, and 

 also to increase the force of its fall, it is 

 necessary that it should be perfectly- 

 straight, nor should it ever be struck with 

 a mallet, &.c. to force it down, because a 

 blow might bend it, and it would easily 

 break afterwards. A bit, like that of an 

 auger, proportioned to the thickness of 

 the rod, may at any time, when necessary, 

 be substituted instead of the steel point, 

 to draw up a sample of the substance from 

 the very bottom of the sounding. 



BORING, in a general sense, the art of 

 perforating, or making a hole through any 

 solid body. 



BOHTNS, in mineralogy, a method of 

 piercing the earth with scooping irons, 

 which being drawn back at proper times, 

 bring up with them samples of the differ- 

 ent strata through which they have pass- 

 ed ; by tue examination of which the 

 skilful mineralogist will be able to guess 

 whereabouts a vein of ore may lie, or whe- 

 ther it will be worth while to open a mine 

 there or no. 



BOUJXCJ of water -pipes. The method 

 of boring alder poles for water-pipes is 

 thus .- being furnished with poles of a fit 

 size, horses or tressels are procured of n 

 due height, both to lay the poles, and rest, 

 the auger on in boring ; they also set up 

 a lathe, whereby to turn the lesser ends 

 of the poles, and adapt them to the cavi- 

 ties of the greater ends of others, in order 

 to make the joint shut each pair of poles 

 together. The outer, or concave part, is 

 caiied 'he female-, and the other, or inner, 

 the male part of the joint. In turning 



