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A HISTORY OF INLAND TRANSPORT, by E. A. Pratt, published by Kegan Paul, Trench, Trubner and Co., Ltd., Carter Lane, E.C.—This book, the first of a series entitled " National Industries," edited by Henry C.B., rivets attention by reason of its authoritative treatment. The author is an authority on transport, and has made modes of transit his particular study. The volume under notice is particularly well written, and the whole subject of Inland Transport in Great Britain. from the earliest times to this present year of grace, is exhaustively treated. Although the author approaches his subject from a scientific view-point, he has not lost sight of the fact that. technical publications are apt to become, to the untechnical reader, extremely heavy readin,g, and, recognizing that even the man in the street is interested in roadways, canals, railways, and various other means of passenger and goods transport, the author has enlivened his pages by many references to well-known historical places, people and occurrences.
Starting from the period when the only roads in these isles consisted of muletracks through bog and marshland, the reader is led onwards through the era of the first rude unsprung coaches to the flying-coach era, the turnpike era, river transport, and then to the extremely fascinating subject of the early days of steam and railways. Tramways have been impartially and fully treated, and the big revolutionary acts which brought them into being have been given full notice. The author indicates, towards the close of the book, in the chapter on tramways and motorbuses, how extremely difficult it is to say what. will become the predominant factor in goods and passenger transport– petrol or steam.
The book should be closely read by every person interested in road traffic.
VALVES AND VALVE GEARING; by Charles Hurst, published by Charles Griffin and Co., Ltd., Exeter Street. Strand.—This publication, which consists of 285 pages of text, and is profusely illustrated, is a most-comprehensive review of valves and their necessary operating mechanism, as used for both modern steam and internal-combustion engines.
The author, who is chief draughtsman for Davey, Paxman and Co., Ltd.. has confined himself almost entirely to descriptions of innumerable types and to useful expositions of valve settings and diagrammatic demonstrations of relative motions. It perhaps might have been useful to those who have charge of either the design or the maintenance of engines of all kinds, if this volume, which, by the way, is now in its sixth edition, had contained more matter dealing with the advantages and disadvantages of the many different kinds of valves. The reader would have found it instructive, undoubtedly, to have had the, result of the author's necessarily extensive experience with regard to the drawbacks of a more or less important character which pertain to all the different types described. All those who know anything of the design and operation of valve mechanism realize only too well that even the most-skilful innovation of this kind is more or less of a compromise. As a matter of fact, there is little in Mr. Hurst's book which enables a choice to be made between gears, which on the face of it appear to have equal claims to the consideration of the user.
It must not be assumed from the foregoing criticism, however, that Mr. Hurst's writing does not contain a great amount of information on this special subject. He appears to have collected in this latest edition structural particulars of almost, every accepted type of valve mechanism with one notable exception, and that is the valve gear and settings of modern high-speed, internalcombustion engines. Piston speeds and engine efficiencies in these types have been so much improved during the past year or two, that the lessons to be drawn from construction of this class are undoubtedly of the utmost value to builders and users of even the largest steam and gas engines. Data are new available, which but a few years ago were almost undreamt of. It, too, would have been useful to have discovered in this volume some attempt to collate the very many modifications of the sleeve-valve type, which has created so great a constructional change in many of the latest forms of internal-combustion engines.
Valves and valve gearing " is divided into live parts, and, as might he expected, by far the largest of these is devoted to steam-engine valves. There is much in these early chapters which is interesting to those of us who are primarily concerned with the construction and repair of steam wagons and tractors. The Zenner valve diagram is profusely used in illustrative form throughout the book. All those who have anything to do with the small but efficient steam engines which produce the motive power for modern steam wagons will here find much to instruct them in the matter of valve adjustment., and the effect of the operating mechanism's proportions upon the efficiency of an engine. Designers will do well to refresh their knowledge of the effect of short connecting and eccentric rods, as demonstrated herein.
Some space. is given to the consideration of the use of piston valves in connection with superheated steam. Many of the more-complicated steam-engine valve niechanisms are, of course, of only academic interest to the users of selfpropelled road vehicles. Here and there, however, deductions that, have their lesson for all of us are made in connection with such gears. " A sharp corner." we read, " looks very well on the indicator card, but the effect on the coal bill is insignificant."
Much that is contained in the section dealing with gas-engine valves is, of course, applicable to similar components of the smaller internabrombustion-engine types. Areas of valve openings, sizes of induction pipes, and admissible velocities of gas supply and exhausts are dealt with at length. The demonstration of the ordinary cam motion is clearly set. ont, and is convincing, whilst considerable space is given to the discussion of the permissible clearance between valve spindles and tappets, and the effect of rise of temperature on such clearance. The possibilities of water injection may yet claim increasing attention from the designers of small internal-combustion engines. A useful section is that devoted to pump valves of all kinds, and to safety and relief valves for steam engines. MOTOR BODIES AND CHASSIS, by H. J. Butler, published by Harper and Bros., 45, Albemarle Street, W.—A foreword by Lord Montagu of Beaulieu, the Editor of " The Car Illustrated," is to be found in this publication, recommending its contents to motorists of all kinds, to students and workmen of the coachbuilding trade, and to the public generally. The best feature of this book is undoubtedly the reproduction of a number of well-drawn designs for carriage bodies of many standard types and of the latest patterns.
To the coachbuilder all that, Mr. Butler has to say with regard to the actual construction and finish of carosserie is bound to be useful. He also indicates to the motor-body draughtsman much that many of them know, and still more that many of them should know and do not. The methods of preparing the material, of -the use of modern wood-working machinery, and the superseding of many of the old rule-of-thumb methods form interesting reading in Chapter VII., and the author has much that is instructive to say with regard to such special features of the coachworker's business as the proper use of coach irons, the satisfactory hanging of doors, and the fitting of hood and screen ironwork.
Nothing, or, at any rate, very little is said of the very many special types of bodies which the commercial vehicle has brought into use. In many cases the modern industrial motor carries, for the sake of advertisement as much as for any other reason, a body whose painting and finish bears close comparison with the finest. carosserie that is to be found on high-class touring cars. The subject of the coachwork for commercial vehicles is, if anything, one which calls for more exhaustive treatment than that of the less utilitarian branch. We think Mr. Butler might well have omitted much of that part of his volume which deals with the chassis itself, and the latter part of the book might have been devoted to the construction of commercial-vehicle bodies.
The sections which are devoted to spring construction, and to wheel manufacture are instructive; we note that the author speaks favourably of the Lynton.
The last chapter of the book, and a very meagre one at that, is concerned with commercial motoring and its cost. We read : " So far, the greater majority (eie)of motorcars are (sic) utilized for pleasure purposes. If the mechanicallypropelled vehicle is to largely supplant (sic) horse-drawn traffic as a:whole, then there is still an enormous field open to the 'manufacturer of commercial-motor vehicles." Later we read " The expense connected with running any type of car depends on several circumstances." This is hardly informative. There, too, is a lack of aiscrimination in the statement: "50 miles a day may be looked upon as an all-round paying mileage with e minimum of 200 days running per annum." Again : "A complete steam vehicle with load costs between £500 and £600." We respectfully suggest that the nature of the load, whether it be kerbstones or cameras, should have some slight bearing on the cost.
As to tires, the author says these " can be obtained on a 10,000 mile guarantee basis, and with careful driving a tire will last even longer." Think of those much-advertised 40,000 miles.