Those who have occasion to tow racing cars or other valuable objects in trailers, or trail anything behind a racing-car transporter, should he interested in anything which enhances the safety of such a vehicle. The other day we attended a demonstration at Blackbushe Aerodrome of the Mathews-Henry Hydraulic Overrun Trailer Brake Actuator. A battered 5-cwt. Thames van pulling an empty trailer 76% its own weight was used to prove that this safety mechanism caused the trailer, when jettisoned from 40 m.p.h., to pull up in a short distance in a straight line without any “fireworks.” An intrepid journalist rode on the trailer on one demonstration run, showing the confidence inspired by the previous runs! The device, well-known to the Army and R.A.E., has other advantages and is quite inexpensive. It is worth investigation by all trailer operators. The makers are Mathews Hydraulics, 67, Jeddo Road, W.12.—W. B.