Sentence:  The softest and almost the cleanest iron for turning for cotton and other machinery is made from wrought iron <WSD>"swarf</WSD>" (or turnings). Sometimes the <WSD>swarf</WSD> is worked by itself, but commonly a ball is made of good <WSD>swarf</WSD>, and while hot, fine <WSD>swarf</WSD> is thrown into the furnace, and the ball is rolled about so that the <WSD>swarf</WSD> adheres to it, and it is then taken to the hammer. 
Meaning of the word marked with <WSD> tags:  The waste chips or shavings from an abrasive activity, such as metalworking, a saw cutting wood, or the use of a grindstone or whetstone. (from mid 16th c.)