SCRAPER BOARDS, MANUFACTURED BY AUGERER & GÖSCHL, VIENNA.
No. 6.—A white scraper board printed with black lines. There are 40 black and 40 white lines to the centimetre; the ratio of black to white is as 1 : 2. At right angles to the black lines impressed lines are arranged, of which 37 are depressed and 37 raised up to the square centimetre.
No. 7.—This is practically the same as No. 6, only that the lines are slightly less in number, namely, 35 black and 35 white and 26 impressed lines in equal areas to No. 6.
No. 8.—This contains dots instead of lines, both black and impressed; there are 1,156 black dots at regular intervals, and 961 impressed dots to the square centimetre.
No. 9 is a smooth scraper board.
Nos. 10 and 11.—These are impressed with straight lines in the proportion of 1 : 1. With No. 10 there are 27 lines, in No. 11, 37 lines to the centimetre.
Nos. 12 and 13.—These are impressed with lines at right angles to one another, so that regular squares are formed. No. 11 contains 730, No. 12, 1,370 squares in every square centimetre.