Lessons in Arc WeldingThis edition of New Lessons in Arc Welding is the 5th revision of a text resulting from an enlargement of the lessons used in the Lincoln Arc Welding School. The text is divided into several areas. Lessons 1. 1 to 1. 48 contain basic information necessary to become familiar with manual electrodes. Lessons 2. 1 to 6. 3 contain information and operating procedures on specific manual machines and electrodes manufactured by The Lincoln Electric Company.