100 sidor A4, ill, hft. Utgivarens beskrivning: This book arose from correspondence with Dante Porta after we had published the English edition of André Chapelons La Locomotive a Vapeur, and the idea of bringing some of Portas papers to a much wider audience was irresistible. Porta has always been described as Chapelons disciple, which is certainly true, but was very definitely his own man, with his own ideas. He also worked in a more technologically advanced age, and whilst this inevitably regarded steam as out-moded, it did give Porta access to materials unknown to Chapelon, and different (computer) design techniques, all of which he used to maximum effect. In my opinion, the fact that Porta never worked within the traditional railway company set-up, being an academic by training, gave him much more freedom to adopt a different approach. And finally, of course, Porta taught and encouraged those brave few who continue to work on the concept of advanced steam power. Contained within this book are three of Portas papers, one public and two previously circulated privately. Porta himself wished us to publish his paper Fundamentals of the Porta Compound System for Steam Locomotives, and this is the core of the book. However, to give an introduction to much of Portas work, and his overall philosophy, we have also included the paper he presented to the Manchester Centre of the Institution of Locomotive Engineers in March 1969 entitled Steam Locomotive Development in Argentina - its contribution to the future of railway technology in the under-developed countries. The third paper is, again, a private one, and deals with the subject of steam leakage.