Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 1, 1802).djvu/316

286&#93; 266] BLI very easy and entertaining manner; we shall first give an account of this machine, as represented in the subjoined cut, rind then conclude with a description of its me- chanism. It consists of a box nineteen inches square in the clear space within, and near two inches deep, divided into cells, containing the figures, lines, Sec. hereafter described, ne- cessary for performing the rules of arithmetic. The lid or cover of the box, which serves as a leaf, or slate, is pierced full of holes in parallel rows ; the first row has eighteen large, and seventeen small holes, alternately placed ; the se- cond row, eighteen small holes, placed under the above large ones ; the third, as the first, and so on alternately, thirty-five rows, the whole cover being full, and con- taining three hundred and twenty- four large holes, and six hundred and twelve small ones, which make an exaft square. The figures are represented bv pegs with cubical heads, and distinguished by pins C BLI placed on one side in the following manner : — One, is expressed by a pin's point, on the right-hand ; two, by the same in the middle ; and three, by having it on the left- hand ; four, five, and six, by pins' heads in the above three different situations 3 seven; eight, and nine, by crooked pins, or staples; in the same manner : the cypher is un- derstood by a plain peg,- without any mark. On the top of each peg is printed the figure which it repre- sents, to render the work intelligi- ble to any person that may see it, without being acquainted with the marks. These pegs are made to fit the large holes. Pieces of bras* wire, bent to a right angle, about half an inch from each end, and made to fit the small holes, serve for the purpose of lines, to separate the different parts of the work. The box contains twenty-eight partitions, situated as in the fol- lowing cut, ten of them to hold figures, and the others for the lines of different lengths. A, The