Although in recent years the work of the stirling Engine Society has enormously increased the popularity of Hot Air engines, and many model engineers have taken to building various types, many find the workings of the Stirling engine to be shrouded in mystery. Visitors to exhibitions look in amazement at engines which will run on just the warmth of their hands or the heat coming from a jug of hot water. While they might not know his name, author Robert Sier would certainly be recognised by many of these visitors for in company with Roy Darlington, he spends a great deal of his time in support of the Stirling Engine Society at events at which hot air engines are displayed and run.
The principle of heating air to obtain power has been known for centuries. The Montgolfiers' hot air balloon of 1783 was one of the first successful attempts at harnessing the energy in hot air to provide useful work and, over the years many weird and wonderful ideas and designs have been put forward to increase the efficiency of the Hot Air and Stirling engines.
In this major work Robert Sier has expanded an earlier work to present a comprehensive history, one which I feel will become definitive in its field. Most of us are aware of the hot air driven fan, which I believe may still be available, but how many of us have seen an automatic piano or organ? Using punched paper rolls or punched cards the upright Verdi could play for10 hours non-stop. The Euphonika Musikwerke of Leipzig manufactured the Motor-Manopan, a reed organette powered by two Heinrici motors.Hot air engines were not just for novelties, in a catalogue of 1893 a Bailey Vertical hot air engine is shown driving a printing press as used at a military camp. Such uses were ideal since any material which could be burnt could be used to provide power.
Commercial development continued until the 1970s but this is far from the end of the story. members of the Stirling Engine Society have continued the development using modem materials and techniques not available to earlier generations, and interesting designs and ideas are still being developed.
With sections devoted to Fluid Displacement devices, Early Designs, Furnace Gas Engines, Displacer Type Gas Engines, Free Piston and free Displacer Engines, John Ericsson and Open cycle Engines, The Compression Engine,Vacuum Engines. Heat Pumps and Air compressors, for anyone interested in the history of the Hot Air Engine, this copiously illustrated book is a must. With over 330 pages it is beautifully produced and printed on high quality paper. and the case bound buckram cover gives the volume a fine feel of quality. At £32 post free (UK) some may feel that it is a little expensive, but compared with the cost of some railway "picture" books it is a quality product and is highly recommended.