PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 473 



The motive power of machinery to move the needles, one of which 13 

 straight and pierced with tiiree eyes at tlie point, while the other is curved 

 and has two eyes, is entirely below the bed plate. The straight needle is 

 attached to an arm or shank which projects through a slot above the bed 

 plate, and this is fastened to a mandrel working from below; underneath the 

 bed plate is a disk upon which are placed the spools, tensions, &c., and 

 working through which, in a slot, is the curved needle or finger, so called. 



The cloth or garment in which the button hole or eyelet hole is to be 

 worked, being punched, is placed upon the bed plate, the hole being directly 

 over the slot, and the end of the needle shank projecting through it. The 

 cloth is then pressed down upon the plate by what is called a foot or lever, 

 and securely confined. On turning the crank the needle shank rises, and 

 then, in its downward motion, carries the straight needle directly through 

 the edge of the fabric. The curved needle or finger which woiks through 

 the hole brings its thread up over the edge of the cloth'. Tliis thread ia 

 caught by the straight needle in its downward course, then the finger draws 

 it down below the fabric and takes a loop from the straight needle, and 

 ascending gives a loop again to the straight needle, thus forming a double 

 interlacing stitch. 



The disk, which is the most important portion of the machine, is mount- 

 ed on a travelling carriage moved backward and forward by a screw. 



When the operator starts the machine, the needles being at the lower 

 end of the button hole are moved along the edge or straight side by the 

 screw feed; on reaching the end the screw feed is disconnected from the 

 disk by a switch, and a gripe or rotating movement carries the needle 

 around the end of the hole, forming a pcrfe(;t crescent; so soon as this half 

 circle is complete the»switch again pushes the screw into position, and this 

 by a reverse motion drives the needles dawn the other side of the hole to 

 the point of departure, forming a complete button hole. 



The size of the button hole is readily regu'ated by an index attached to 

 the machine, and it will work a hole two inches in length, or an eyelet of 

 less than an eighth. 



An ordinarily skilful operator will, with the assistance of two girls to 

 finish or tie the ends, work one thousand fine button holes an inch and a 

 quarter in length in ten hours, and all exactly alike. By the hand not more 

 than forty can be made by the most accomplished operator in the same 

 time. 



As stated, the range of this stitch is not confined to button hole making, 

 but includes the sewing of sails, tents, awnings, indeed all classes of work 

 requiring two straight or selvage edges to be bound securely and smoothly 

 ■ together. 



Improved Kettle for Boiling Water. 



Mr. Seaman also exhibited an improved kettle for boiling water. It was 

 made with a hollow bottom separated some two inches from the ordinary 

 bottom of a kettle, and held to it by three or four small tubes through 

 which the water circulates. This arrangement gives three times the heat- 

 ing surface of an ordinary kettle. Mr. Seaman said he had boiled seven 

 quarts of water in less than seven minutes. The circulation upward 

 through the tubes connecting the two bottoms was so great that a handfull 



