OR UNIVERSAL DICTIONARY OF THE ARTS, SCIENCES, LITERATURE, &c. INTENDED TO SUPERSEDE THE USE OF OTHER BOOKS OF REFERENCE. ILLUSTRATED WITH THREE HUNDRED and seVENTY PLATES AND MAPS. SECOND EDITION, IN TWENTY-THREE VOLUMES. VOLUME XV. EDINBURGH: PRINTED BY JOHN BROWN, ANCHOR CLOSE, FOR THE PROPRIETORS, AND SOLD BY ALL THE BOOKSELLERS in the United KINGDOM. 1816. ENCYCLOPÆDIA PERTHENSIS. MIN (1) MINE. n.f. mine, French; mwyn or maun, Welsh, from maen lapis, in the plural meini.] 1. A place or cavern in the earth which contains metals or minerals.la your large heart was found a wealthy mine. Waller. -A workman, to avoid idlenefs, worked in a Ove or mine pit thereabouts, which was little efeemed. Boyle.-A mine-digger may meet with gem, which he knows not what to make of. Byle-The heedlefs mine-man aims only at the btaining a quantity of fuch a metal as may be readible. Boyle. 2. A cavern dug under any forfication that it may fink for want of fupport; or, modern war, that powder may be lodged in it, which being fired at a proper time, whatever is over it may be blown up and destroyed. What mine hath erft thrown down fo fair a Sidney. Build up the walls of Jerufalem, which you have broken down, and fill up the mines that you tower? tave digged. Whitgift. Others to a city frong MIN bafe is double the height taken from the centre of the mine. 4. That when the mine has been overcharged, its entonnoir is nearly cylindrical, the diameter of the upper extreme not much exceeding that of the chamber. 5. That befides the fhock of the powder against the bodies it takes up, it likewife crushes all the earth that borders upon it, both underneath and fidewife. To charge a mine fo as to have the most advantageous effect, the weight of the matter to be carried must be known; that is, the folidity of a right cone, whofe bafe is double the height of the earth over the centre of the mine: thas, having found the folidity of the cone in cubic fathoms, multiply the number of fathoms by the number of pounds of powder neceflary for raifing the matter it contains; and it the cone contains matters of different weights, take a mean weight between them all, always having a regard to their degree of cohesion. Ás to the difpofition of mines, there is but one general rule, viz. that the fide towards which one would determine the effect be the weakeft; but this varies according to circumstances. The calculation La fiege, encamp'd; by batt'ry, fcale, and mine, of mines is generally built upon this hypothefis, Alfaulting. Milton. That the entonnoir of a mine is the fruftum of an Ste MINE, II. in laft volume, P. 720. From dius of the excavation of the mine, and the diaMINE, in the military art, (§ I. def. 2.) inverted cone, whofe altitude is equal to the rabeat number of experiments, it appears, 1. meter of the whole leffer bafe is equal to the line That the force of a mine is always towards the of leaft refiftance; and though thefe fuppofitions weakeft fide; fo that the difpofition of the cham- are not quite exact, yet the calculations of mines ber of a der must be greater or lefs in proportion to the be followed till a better and more fimple one be debis effect. 2. That the quantity of pow- practice; for which reafon this calculation fhould greater or lefs weight of the bodies to be raised, found out. M. De Valliere found that the entonmuft allow for each cubic fathom of loofe earth generated by the rotation of a semiparabola about nd to their greater or lefs cohesion; fo that we noir of a mine was a parabaloid,. which is a folid 11. Of firm earth and ftrong fand, 11 or 115. Of flat clayey earth, 15 or 16 lb. Of new is very infignificant in practice, that of the fruf its axis, but as the difference between thefe two rafonry, not of old mafonry, well bound, 25 or 30 lb. 3. tum of a cone may be used. Α cularly |