(156) The teeth can be set in the foundation in three ways—either plain, twilled, or ribbed, these settings being shown in Fig. 76, the dots representing the wire points, the back of the teeth being shown by the dotted lines. In the first case the teeth are in straight lines; in the second they are, as the name implies, set diagonally; while in the third they are in straight lines, but set so that they are in sets of three, each of which overlaps its predecessor. Generally, plain setting is very little used, fillets being commonly made ribbed, except in the case of the flat covering, which, when mild steel wire is employed, is usually twilled. In manufacturing cards for covering the flats it is common to commence with a large sheet equal in width to the length of the flat. The teeth are then set for a space equal to the width of the flat, when the sheet is rapidly traversed longitudinally until the point for starting a new flat strip is reached. These strips are cut out of the sheet, and thus leave the necessary margins for fastening to the flat. In America twilled setting is preferred, but, in this country, it is objected that spaces are left between each lap when fixed on the cylinder, which is very objectionable. This fault does not occur where ribbed fillets are used, and it is now almost the universal practice to use this setting for cylinder and doffing coverings. However the teeth are set in this respect, they vary also in their distance from each other, and this variation depends on the “counts” of the wire. This phrase is used to indicate the fineness of the pitch of the wire teeth, and the method of counting is based on the number of teeth in the width of the sheets formerly made. Thus, if there were 100 teeth in a sheet four inches wide, the counts were said to be 100’s, the same rule being applied to-day. Longitudinally, the pitch of the teeth was ten “crowns,” or points, to the inch, this being also retained as a standard of measurement. In this way it is possible, by knowing the counts of wire, to calculate easily the number of teeth per square inch. Thus, in the instance named, there would be 100 × 10 = 1,000 teeth in the four inches of width by one inch in length, which is equal to 250 teeth in every square inch.