We incline to the opinion that, though the machine of the patent .is an improvement over those of the prior art, the changes which produced this result were quite obvious and did not require the skill of the inventor. What Wendell accomplished had substantially been done before, and when the new demand came for larger machines the prior art showed the skilled mechanic how to construct them. The entire subject has been carefully considered by the judge of the Circuit Court, and nothing need be added to his opinion (171 Fed. 870). The decree is affirmed.