Complex sentence: On graduating he was employed as an assistant engineer for the Fowler, Waring Cables Company, which supplied the telegraph, telephone, and electicity supply industries, and was first sent to take charge of the company's cable networks in Ostend and Grenoble.
Split into simpler sentences: On graduating he was employed as an assistant engineer for the Fowler, Waring Cables Company, which supplied the telegraph, telephone, and electicity supply industries. He was at once sent to take charge of the company's cable networks in Ostend and Grenoble.