MECHANICS AND USEFUL ARTS. 79 



the axle just at the inner edge of the bearing, and a ring of thin metal was 

 bolted to the inside of the limb hi such a manner as to take hold of this collar 

 and prevent the slipping of the wheel endwise. This allows the end of the 

 hub to be boxed completely in, keeping out the dirt and preventing the pos- 

 sible appearance of grease and filth at these prominent points on an elegant 

 carriage. Green's Sleeve- Axle is simply an improvement on this "mail- 

 coach" style, and has the effect of making the axle last longer in fact, last 

 forever, in theory, as the wear is entirely removed. The collar and the whole 

 bearing surface of the axle are made in a separate piece or sleeve, and fitted 

 tightly on over the true axle. The true axle is wrought iron, and forged 

 octagonally and tapering at the extremities. The sleeve is of cast iron, and 

 when worn a little on one side, may be removed and turned one eighth 

 around, in as many hours as it required days to repair the solid axle. TVhen 

 all eight of its sides are sufficiently worn, the sleeve has only to be rejected, 

 and a new one supplied. The patentee is E. H. Green of Baltimore. 



IMPROVED CYLINDERS FOR CALICO PRINTING. 



In printing fabrics by the ordinary system, the copper rollers employed are 

 found to be easily affected by the chemical action of the mordants, colors, and 

 other matters employed in calico printing ; and great expense is occasioned 

 by the large outlay necessary for the production of the engraved metallic 

 rollers, which are not only very costly, but from the reasons above-named, 

 are far from being durable. It is proposed to obviate these disadvantages, by 

 employing cylinders covered with india-rubber or gutta-percha, which mate- 

 rials are afterward vulcanized and rendered extremely hard. Thus prepared, 

 they are engraved in the same manner as ordinary copper printing cylinders 

 or rollers, whether in intaglio or relief. Such printing surfaces are produced 

 with facility and economy, while their printing action is sharp and effective, 

 and not subject to injury from the action of acids, alkalies and other agents 

 employed. 



IMPROVED MACHINERY FOR PICKING FIBROUS SUBSTANCES. 



In machines for picking cotton and other fibrous materials, the picking 

 cylinder is generally covered with what is termed a " fillet ;" this consists of a 

 sheet of leather filled with ordinary card-teeth. The heavy work at which 

 pickers are employed requires that the teeth should be very firmly secured 

 else they break, bend or otherwise refuse to do good work. A recent im- 

 provement by Mr. Kitson of Lowell, consists in making the teeth separate, 

 and in attaching them, without any fillet to the cylinder. His mode of 

 attachment is such that they may be made larger and stronger, with corre- 

 sponding advantages hi durability, economy and thoroughness cf operation. 



IMPROVEMENTS IN LOOMS AND WEAVING. 



Broadbent's Improved Loom. The principal feature of this invention by 

 John Broadbent, of Oak Grove, Kentucky, consists in the employment of two 



