ONE:"After the soldiers had performed their duty as vandals and bandits they set the houses on fire. Soon the whole town was one immense pool of fire.The difference between how machinery is constructed and why it is so constructed, is a wide one. This difference the reader should keep in mind, because it is to the second query that the present work will be mainly addressed. There will be an attemptan imperfect one, no doubt, in some casesto deduce from practice the causes which have led to certain forms of machines, and to the ordinary processes of workshop manipulation. In the mind of a learner, whether apprentice or student, the strongest tendency is to investigate why certain proportions and arrangement are right and others wrongwhy the operations of a workshop are conducted in one manner instead of another? This is the natural habit of thought, and the natural course of inquiry and investigation is deductive.
TWO:The first of these operations includes all threading processes performed on lathes, whether with a single tool, by dies carried positively by slide rests, or by milling.The adaptation, endurance, and cost of machines in designing become resolved into problems of movements, the arrangement of parts, and proportions.
