With the simple level illustrated the proper grade and levels for drains, ditches, roadways, concrete floors, foundations for houses, and for bridges, etc., can be laid out. In fact, all sorts of levelling can be easily and readily done with this instrument. Fig. 1 shows an elevation of the complete instrument; A is a builder's ordinary level fitted with a pair of Stanley's improved level sights BB. The level is placed on a table C that can be set level by means of four thumbscrews D and sighted in any direction. In the figures, E is a triangular block of hardwood to which are fastened the parallel plates C, and also the three legs by three screws G; H is a small brass eye screwed into the centre of the underside of the triangular block to suspend a plumb-bob if it should be required to place the instrument over a point. Fig. 2 is a section showing dimensions of the parallel plates. The top plate should be of two pieces glued and screwed together, cross-grained to prevent twisting. In the centre is fastened, by means of a brass screw, the ball J for the ball-and-socket joint. In the centre of the top piece of the bottom-plate a hole is made to fit the ball to form the socket of the joint. Before glueing the two parts of the bottom-plate together, the triangular block of hardwood ( 3 1/2 in. long with 2-in. sides) must be screwed to the bottom-piece on the under-side. The thumbscrews on the lower plate are equally spaced 3/4 in. from the outer edge. On the under-side of the top-plate over the point of the thumbscrews, and for them to bear against, small brass plates K K, Fig. 2, should be fixed. The levelling staff can be made by painting the divisions on a strip of 3/4- in. board, or, if preferred, papers printed with the divisions can be obtained and pasted on the board. The instrument is set up and used in the same way as an ordinary dumpy level.

A Simple Level.

Fig. 2. A Simple Level.

Blaking a Wringing Machine.

Blaking a Wringing Machine.