sentences:  This tributary was famous for its rich jasper pebbles; semi-precious stones, which were collected, cut and polished for use in jewellery.The gravel bed of rivers was an important source of income for millers and others who owned the rights of extraction.The gravel was sold for various farm and horticultural purposes, such as infilling drainage ditches, the surfacing of field entrances and driveways, road surfaces, horticulture, etc.