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The paper gives an account of some of the mechanical difficulties experienced in the development and operation of experimental plant for the hydrogenation of coal and tar for the production of motor spirit. Particulars of the various stages of progress are given, from small autoclaves up to a continuous plant capable of producing up to 300 gallons of spirit per day. The pressure plant is operated at 3,000 to 6,000 lb. per sq. in., and at temperatures up to 950 deg. F. Hydrogen produces complete disintegration of the structure of mild steel under the higher temperature conditions. The use of special alloy steels reduces the liability to hydrogen attack, giving longer working life and allowing higher working pressures, but satisfactory service can best be obtained by insulating the pressure-resisting walls from the heating medium so as to avoid heating the metal beyond 200 deg. F. Various methods of making suitable joints for high-pressure pipes and cylinders are described, and the results of microscopic examination of sections of cylinders are given in Appendixes.

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This chapter showcases practices and processes that have research-based promise for making the active pursuit of teacher expertise an important and valued part of a teacher's career and school culture. Authors share habits and practices of teachers who pursue mastery and expertise as well as the professional learning methods of practitioner inquiry, lesson study, and professional learning communities. These approaches serve as potential vehicles to build ongoing professional learning and student-centered school improvement as a critical component of what it means to teach. Through collective processes, schools are able to address a multitude of issues related to student success, classroom innovations, and better working conditions for educators. When these processes are valued, supported, and sustained, they can lead to increased professional drive and joy of teachers as they grow in their sense of professionalism, self-efficacy, and purpose.