Installment No. XX of a series on textiles at the 1873 Vienna Exhibition, by Dr. H. Grothe, published in Engineering on March 6, 1874. It describes a continuous carding machine by Oscar Schimmel and Co. of Chemnitz that also spins coarse carpet yarns, and then gives a detailed mechanical account of John Avery's American continuous wool-spinning machine. The Avery description covers the nipping wheels, cam-controlled drafting, twisting tube, drawing rolls and Potter's patent spindles. Engraved figures and mechanical diagrams accompany the text.