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1 Preliminaries -- 1.1 The scope of this book -- 1.2 The anatomy of design -- 1.3 The conceptual stage -- 1.4 General aids to design -- 1.5 Combinative methods: tables of options -- 1.6 Repêchage and reviews -- 1.7 Recurrent problems in design -- 1.8 Combination and separation of functions -- 1.9 Summary -- 2 Structures -- 2.1 Introduction -- 2.2 Structural elements: rods, ties and struts -- 2.3 Beams -- 2.4 Plates -- 2.5 Torsion -- 2.6 Thin-walled pressure vessels -- 2.7 Contact stresses -- 2.8 An example: bathroom scales -- 2.9 Bathroom scales: refinements and details -- 2.10 Springs -- 2.11 Structures, springs, energy and stiffness: pertinacity -- 3 Abutments and Joints -- 3.1 Introduction -- 3.2 The form of abutments -- 3.3 Screwed fastenings -- 3.4 Joints -- 3.5 Stator blade fixing -- 3.6 Joint efficiency -- 3.7 Offset bolted joints: lugs -- 3.8 General principles applied to joint design -- 3.9 Register in joints: intersection problems -- 3.10 Alternating loads on bolted joints -- 3.11 Sealing -- 4 Freedom and Constraints: Bearings -- 4.1 Degrees of freedom -- 4.2 Shafts and bearings -- 4.3 The principle of least constraint: kinematic design -- 4.4 Epicyclic gears -- 4.5 Bearings -- 4.6 Hydrostatic bearings -- 4.7 Hydrodynamic bearings: squeeze action -- 4.8 Hydrodynamic bearings: wedge action -- 4.9 Rolling-element bearings -- 5 Various Principles -- 5.1 Insight and abstraction -- 5.2 Biasing -- 5.3 Force paths -- 5.4 A cylinder head joint -- 5.5 Bevel gear mounting -- 5.6 Gear pump -- 5.7 Nesting and stacking -- 5.8 Guiding principles for choosing nesting orders -- 5.9 Other aspects of nesting -- 5.10 Summary of guiding principles for nesting orders -- 5.11 Flexural elements -- 5.12 Easements -- 6 Materials and Manufacturing Methods -- 6.1 Introduction -- 6.2 Materials, manufacture and design philosophies -- 6.3 The effect of density -- 6.4 Choice of material -- 6.5 Figures of merit -- 6.6 The relation between form and manufacturing method -- 6.7 New materials and processes -- 6.8 Aids to material selection -- 7 Pneumatic Quarter-turn Actuators -- 7.1 Introduction -- 7.2 Fundamental considerations -- 7.3 Aspect ratio -- 7.4 Table of options -- 7.5 Studying a combination -- 7.6 Two good designs -- 7.7 Summary -- 8 Epicyclic Gears -- 8.1 The function of the planet carrier -- 8.2 Increasing the stiffness by asymmetry -- 8.3 Local form design -- 8.4 Joint location and design -- 8.5 'Alexandrian' solutions -- 8.6 The choice of embodiment -- 8.7 Another solution -- 8.8 Other aspects of epicyclic gearing -- 9 Hydraulic Pumps -- 9.1 The swash-plate pump -- 9.2 Valve plate design -- 9.3 Eliminating the valve plate -- 9.4 Virtues and limitations of the swash-plate pump -- 9.5 The bent-axis pump -- 9.6 An elegant bent-axis pump -- 9.7 Combining the virtues of swash-plate and bent-axis -- 10 Miscellaneous Examples -- 10.1 Connecting rods -- 10.2 A suitcase handle and a suspension arm -- 10.3 A window stay -- 10.4 The Challenger disaster -- 11 The Principles of Design -- 11.1 An emerging discipline -- 11.2 Least constraint and kinematic design -- 11.3 Separation and combination of functions -- 11.4 Design mating surfaces or abutments -- 11.5 Clarity of function -- 11.6 Short direct force-paths -- 11.7 Matching and disposition -- 11.8 Nesting order and related principles -- 11.9 Avoiding arbitrary decisions: combining good features.

Within the lower middle‐class, British commercial travellers established a strong fraternal culture before 1914. This article examines their interwar experiences in terms of income, careers, and associational culture. It demonstrates how internal labour markets operated, identifies the ways in which commercial travellers interpreted their role, and explores their social and political attitudes.