Page:Model Steam Locomotives by Greenly Henry.pdf/7

 Author’s Preface include many complete designs in this volume. The author possesses a large number of full-size blue-print diagrams of complete locomotives, which drawings can be used in conjunction with the components here illustrated and described. He can also be readily approached through the publishers. Although there has been considerable increase in model locomotive work since this book was first issued, only minor corrections have been found necessary in the text of this edition. The principles of the steam locomotive remain the same in spite of all the progress made. This development is reflected mainly in the greater efficiency obtained in the recent L.M.S.R. “ Royal Scot ” and G.W.R. “ King ” type locomotives. Careful designing rather than revolutionary changes has so far been the rule, however. The poppet valve and cam reversing gear are on trial against the piston valve and Walschaert's motion. In the model world the writer designed for the late Count Zborowski his largest model, 1/3rd scale Pacific engines which are now operating quite successfully on the Romney, Hythe, and Dymchurch 15-inch gauge railway, a line which the writer has recently equipped throughout. H. G.