{"content":[{"text":"1","bbox":{"left":0.495462,"top":0.067941,"width":0.010084000000000037,"height":0.01578299999999999}},{"text":"THE GENESIS OF THE THERMIONIC VALVE \n A lecture given to the Institution of Electrical Engineers in 1954 on the fiftieth \n anniversary of the invention of the thermionic valve.","bbox":{"left":0.095462,"top":0.115552,"width":0.805839,"height":0.07193900000000002}},{"text":"By Professor G. W. O. HOWE, D.Sc., LL.D., Member","bbox":{"left":0.17479,"top":0.202513,"width":0.6507339999999999,"height":0.021228999999999998}},{"text":"Prof. Howe is Emeritus Professor of Electrical Engineering, \n University of Glasgow.","bbox":{"left":0.190588,"top":0.245637,"width":0.6124430000000001,"height":0.03769699999999998}},{"text":"Lecture delivered before The Institution 16th November, 1954","bbox":{"left":0.159328,"top":0.305257,"width":0.681462,"height":0.01857599999999998}},{"text":"I FEEL honoured in being invited to give the opening lecture at this celebration of the jubilee of the \n invention of the thermionic valve. I feel that I cannot begin the lecture in a more appropriate manner \n than by trying to give you a picture of the inventor himself, for I realize that to many of the younger \n members of The Institution he is little more than a name. \n John Ambrose Fleming was born at Lancaster in 1849, but when he was five years old the family \n moved to North London. His father, a clergyman and a doctor of divinity, was born at Kelso, in \n Scotland, of an old Scottish family of Flemish origin, as the name shows. At the age of 14 young \n John was sent to University College School , a day school conducted at that time in a wing of \n University College in Gower Street, where he was later to be Professor of Electrical Engineering. \n Although his interests were mainly in machinery and scientific matters, he had to work hard at Latin \n and Greek in order to pass the London Matriculation examination, which he did when he was 16. \n He was then entered as a science student at the College. After two years he passed the first part of \n the Bachelor of Science examination, but owing to family financial difficulties, the classes for the \n second part had to be fitted in with work as a clerk in a Stock Exchange office. Fortunately the \n office hours were short and he had plenty of time for his scientific studies. He worked in this office \n for about two years, strange though it seems in these days for a student to have to interweave his \n classes with work in an office. \n In 1870 he passed first class in the Bachelor of Science examination and obtained a post as science \n master at Rossall School, near Fleetwood, with chemistry as his main subject; he was then 21. After \n two years, however, he decided to resume his studies and went to the Royal College of Science, \n South Kensington. He worked there as a research assistant in the chemistry department and shared \n in the teaching work in the advanced chemical laboratories. In 1874 Professor Guthrie, the \n Professor of Physics at the College, founded the Physical Society, and at his suggestion Fleming \n read a paper at the opening meeting on some work which he had been doing on the voltaic pile. In \n the same year he left the College and went to Cheltenham College, again as a science master. \n Having obtained a copy of Faraday's \"Experimental Researches,\" he followed up some of Faraday's \n experiments, and at the Bristol meeting of the British Association in 1875 he read a paper on the \n currents induced in liquids moving in magnetic fields. \n In 1877, after three years at Cheltenham, he once again became a student and went to Cambridge, \n where he won an entrance exhibition at St. John's College. The urge to take this step was largely \n due to Clerk Maxwell's writings, which he had tried to study. He was at Cambridge from 1877 to \n 1881, four years. He says that \"As a teacher, Maxwell was difficult to follow, but everything which \n he did or said bore the mark of genius and the utmost care.\" It is surprising to learn that during some","bbox":{"left":0.095462,"top":0.347989,"width":0.809487,"height":0.568752}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}