The English climate is too cold for rearing silkworms, but a silk industry developed in the late Middle Ages processing imported thread and producing silk goods. The art of making silk thread was developed in England by the silk throwsters of London, Leek (Staffordshire), Macclesfield and Congleton (both in Cheshire). The silk thread is reeled off the cocoons in the country of origin and bundled for shipping. When received in England it is thus ready for throwing, which involves five processes - winding, cleaning, spinning, doubling, and lastly the throwing itself which results in a rope-like thread which is both strong and elastic. Bush gives details of these processes and describes their mechanization during the 19th century. Another process to use the considerable amount of waste silk arising from the above processing was developed from the late 17th century and was termed silk waste spinning (Bush).