Push-rod O.H.V.

Although John Bolster has declared that push-rods and rockers are an untidy makeshift and it is time that they were gone (Autosport, February 15th), Guest Keen and Nettlefolds Ltd., who have a large share in the push-rod market, and wish to maintain and extend it, have instituted a survey that has culminated in a paper entitled “Overhead Valve Gear and Push Rods,” by J. N. Tollit, G.I.Mech.E. Duplicated copies are obtainable from the Company.