Its industries include the manufacture of tiles, pasteboard wares and gardening implements, while there are coal mines in the vicinity.
After copies of such reliefs have been taken in gypsum, cement, statuary pasteboard, fossil dust mixed with vegetable oil, or some other suitable material, they are painted.
- a_= = The globe is of pasteboard covered with whiting and parchment, and has a diameter of 507 mm.
But, if the pasteboard be interposed so as to intercept the vibrating segments AOB, DOC, the note becomes much more distinct.
The reason of this is, that the segments of the plate AOD, BOC always vibrate in the same direction, but oppo sitely to the segments AOB, DOC. Hence, when the pasteboard is in its place, there are two waves of same phase starting from the two former segments, and reaching the ear after equal distances of transmission through the air, are again in the same phase, and produce on the ear a conjunct impression.
But when the pasteboard is removed, then there is at the ear opposition of phase between the first and the second pair of waves, and consequently a minimum of sound.
The industry comprises the manufacture of coarse textiles, pasteboard, &c. Its charter as a town dates from 1298, and it was a much frequented market in the preceding century.
Brieg carries on a considerable trade, its chief manufactures being linen, embroideries, cotton and woollen goods, ribbons, leather, machinery, hats, pasteboard and cigars.
In order to ensure for the eye a central position, there is fixed on the upper end of the tube in place of the eyepiece a disk of pasteboard or metal with an axial hole.