The harrow creates a tilth in which seeds can be sown and/or covered, and to remove some of the less noxious weeds. The eighteenth-century harrow comprised four longitudinal timber bars with five iron teeth, or tines, driven at intervals into each bar. The frame was held stable by cross-bars which passed over the longitudinal bars and were secured by pegs. To prevent each tine following in the same track as the one in front of it, the harrow was drawn by harnessing the horse at one corner. Iron harrows appeared at the beginning of the nineteenth century but were not popular at first because they were very heavy and more difficult to repair. They were however able to create a zig-zag profile in which the tines were staggered so allowing the implement to be trailed in a straight line. In the mid 1800’s broken tines were a constant problem until J & F Howard of Bedford invented a way of fitting the tines into the harrow more securely and yet were replaceable. Constructed wholly of wrought iron, the grubber was like the harrow serving the dual purpose of ploughing and harrowing, but subsidiary to both implements since it required great weight and strength. The scarifier was similar in appearance to the grubber but had a triangular frame mounted on three small iron wheels. A lever lifted or lowered the frame of teeth to a suitable depth. Light in construction, this implement was most useful for clearing land fouled with weeds.