536 
Beport on ilie Implements 
expansion, from 7 feet to 10 feet wide. It is easily opened or 
closed by a handle wliicli controls a screw-spindle. It is claimed 
that this makes it more convenient to move through narrow 
lanes, like those in Devonshire, or gateways, and that it is an 
advantage to be able to vary the width of the teeth according 
to the work required, whether for collecting hay or raking 
stubbles, when probably a wide tooth would be best, or for 
clearing a meadow the last time, when a fine tooth would be 
most suitable. 
Messrs. Ben Reid & Co., Aberdeen, exhibited a Road Tracer, 
or Levelling Apparatus. (Art. 3238.) — This consists of a hori- 
zontal sight-tube, having a graduated scale marked on it, show- 
ing the gradients from 1 in 5 to 1 in 240, which is hung on a 
pivot, and swings freely to the perpendicular when the sliding- 
weight is set to the different gradients. It indicates at once the 
rise or fall of the ground at any distance as far as the eye can see. 
When taking levels the weight should move until the sight- 
tube is in line with the mark on a sight-rod ; the figures on the 
plate then show the rise or fall. It cannot easily get out of 
order, as there are no spirit tubes to break or delicate parts to 
damage. 
Messrs. L. R. Knapp & Co., of Faringdon, exhibited (Art. 
334)1) a small one-row drill, " The CoUings," for hand use, fitted 
with reversible cup wheels and interchangeable cog-wheels, so 
that it can be varied to sow four different quantities of seed. 
The wheels can be regulated to any width of row, and it can be ' 
thrown out of gear at will. This is a well-made drill, at a ' 
reasonable price, and very suitable for filling up gaps in the ' 
rows of turnips — when they are extensive — on large farms. 
One novelty of very general utility was exhibited by Mr. A. 
J. Bleiu, of Fawley Lodge, Hythe, Southampton (Articles 3970- 
72). It is a simple plan for releasing horses from the harness' 
in case of accident, or otherwise. It is applicable to both double ' 
and single harness, and to all descriptions of vehicles. It is^ 
inexpensive, and can be fitted to existing vehicles. It is a very 
ingenious apparatus, not likely to get out of order, easily under- 
stood, and worked by any one. 
Messrs. Cottrell & Co., Hungerford, Berks, exhibited an " Im- 
proved Lawn Mower Grinder '' (Art. 4274), for grinding the 
spiral blades and sole 2:)lates of lawn mowers. The barrel of the 
lawn mower revolves on its own beai'ings in brackets fixed on a 
sliding table, and is driven against the face of an emery wheel 
revolving in a contrary direction, and at the same time the 
barrel moves backwards and forwards on a parallel slide against 
the emery wheel. The sole plate also is ground straight and 
