Forgot your password?  
Related Topics

Resources for students & teachers

This eBook from the Gutenberg Project consists of approximately 313 pages of information about On the Economy of Machinery and Manufactures.

239.  Some further reflections suggested by the preceding analysis, will be reserved until we have placed before the reader a brief description of a machine for making pins, invented by an American.  It is highly ingenious in point of contrivance, and, in respect to its economical principles, will furnish a strong and interesting contrast with the manufacture of pins by the human hand.  In this machine a coil of brass wire is placed on an axis; one end of this wire is drawn by a pair of rollers through a small hole in a plate of steel, and is held there by a forceps.  As soon as the machine is put in action, —

1.  The forceps draws the wire on to a distance equal in length to one pin:  a cutting edge of steel then descends close to the hole through which the wire entered, and severs the piece drawn out.

2.  The forceps holding the piece thus separated moves on, till it brings the wire to the centre of the chuck of a small lathe, which opens to receive it.  Whilst the forceps is returning to fetch another piece of wire, the lathe revolves rapidly, and grinds the projecting end of the wire upon a steel mill, which advances towards it.

3.  After this first or coarse pointing, the lathe stops, and another forceps takes hold of the half-pointed pin, (which is instantly released by the opening of the chuck), and conveys it to a similar chuck of an adjacent lathe, which receives it, and finishes the pointing on a finer steel mill.

4.  This mill again stops, and another forceps removes the pointed pin into a pair of strong steel clams, having a small groove in them by which they hold the pin very firmly.  A part of this groove, which terminates at that edge of the steel clams which is intended to form the head of the pin, is made conical.  A small round steel punch is now driven forcibly against the end of the wire thus clamped, and the head of the pin is partially formed by compressing the wire into the conical cavity.

Notes

1.  I have already stated that this principle presented itself to me after a personal examination of a number of manufactories and workshops devoted to different purposes; but I have since found that it had been distinctly pointed out in the work of Gioja.  Nuovo Prospetto delle Scienze Economiche. 6 tom. 4to.  Milano, 1815, tom. i. capo iv.

2.  The great expense of turning the wheel appears to have arisen from the person so occupied being unemployed during half his time, whilst the pointer went to another manufactory.

Chapter 20

On the Division of Labour

241.  We have already mentioned what may, perhaps, appear paradoxical to some of our readers that the division of labour can be applied with equal success to mental as to mechanical operations, and that it ensures in both the same economy of time.  A short account of its practical application, in the most extensive series of calculations ever executed, will offer an interesting illustration of this fact, whilst at the same time it will afford an occasion for shewing that the arrangements which ought to regulate the interior economy of a manufactory, are founded on principles of deeper root than may have been supposed, and are capable of being usefully employed in preparing the road to some of the sublimest investigations of the human mind.

Follow Us on Facebook