MILL-STONE (μύλος, λίθος μυλικός).—The hand-mill used in Palestine consists of two stone discs, from a foot to a foot and a half in diameter, the upper being about 2 in., the lower 3 in. thick. A porous stone of black basalt is preferred, as being sufficiently hard and not so liable as ordinary limestone to become glazed by the friction of the two surfaces against each other (Job 41:24). The stones are usually flat, but not infrequently the concave face of the upper stone rests upon the corresponding convex of the lower one, so as to facilitate the passing out of the flour in the act of rotation. The lower stone is always the heavier of the two, because it is thicker and because it is often a little wider, with a rebate or raised rim; and the upper stone fits into the recess thus formed. The flour then escapes from an opening several inches long where the rim of the lower stone has been cut away. The upper stone has an opening through the centre for the reception of the upright wooden pin projecting from the centre of the lower stone. Into this hole the wheat is poured in the process of grinding. The upper stone has near the circumference a wooden peg a little over two handbreadths in height, and when the stone is being turned by two women (Matthew 24:41), sitting on opposite sides of it, each grasps the peg continuously with one hand and alternately draws it to herself and pushes it away. Partly on account of their position in sitting, and partly to keep the edge of the skirt away from the cloth spread for the flour, they usually draw up the dress to the knee (Isaiah 47:1-2). The sound of the hand-mill grinding the flour for the daily bread was suggestive of home life under conditions of peace and prosperity, and its cessation betokened turmoil and distress (Ecclesiastes 12:3-4, Jeremiah 25:10-11). The μύλος ὀνικός, or donkey stone of Luke 17:2, may simply mean the revolving upper stone of the common hand-mill, as having the more active share in the work of grinding. If the reference be to the larger kind of stone driven by animal or water power, the allusion would be a case of emphatic hyperbole, like the passage of a camel through the slit of a needle (Matthew 19:24). In Revelation 18:21 it is a strong angel that is described as casting such a stone. See, further, art. ‘Mill,’ with illustration, in Hasting's Dictionary of the Bible .
G. M. Mackie.