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of the men of this country. It is common for us to say, that Scotchmen and Englishmen will succeed everywhere better than other people. It is common to say, "We have beaten them always in the past, and we will always beat them." That is braggadocio. That is not the language we ought to hold towards our fellow-men. I grant you the ability of Scotchmen and the energy of Englishmen; but do you mean to tell me that because your men are better by nature your Society ought therefore to give them a worse education-that because you have a clever man you will give him fewer chances and a worse start than his competitors? I hope I shall hear nothing of the kind; but rather that because Scotchmen are prudent and frugal and sharp-witted, and Englishmen are energetic and pushing and enterprising, they deserve to have the best education you can possibly give them. It is said we are a nation of shopkeepers, and that education is a commodity which is bought and sold, and that it will be regulated by the rule of supply and demand, that it will fetch its own price, and that it ought to be let alone. That is a false principle of political economy, which has misled the English nation enormously, but which has not misled you so much, because I do not believe it is accepted here. This fallacy was first exposed by a Scotchman whose name is dear to you all-the late Dr Chalmers. He said the law of demand and supply does not apply to education, because the law of demand and supply supposes that in proportion to the rarity of a commodity its price is enhanced, and in proportion to the abundance of it it is less valued. With education precisely the contrary is true. Those who are ignorant do not care a straw for education, and those alone who have education value it and want to have more of it. Therefore, it is not the business of the enlightened part of the community to abandon the education of the unenlightened to themselves; on the contrary, it is the duty of the educated to educate the uneducated, and of the enlightened to provide for the enlightenment of the unenlightened. I hope that, accepting this view of duty, you will move the State to grant you the means necessary to carry out such an extension of

your

University system as I have indicated. You have in Edinburgh many clever men, in addition to those in your University, well able to teach the technical sciences; and you ought to bring them all into one systematic institution, so that they might have the advantages of being together, that they might co-operate with and assist each other.

Mr Russell concluded by saying there was much he should have wished to add had time permitted; but if the Society of Arts, the Professors of the University, or the citizens of Edinburgh, would think well of the suggestions he had made, any assistance he had it in his power to render, and any information he could give, he should cheerfully contribute to the furtherance of these purposes.

Notice of some Improvements in Sewing Machines. By EDWARD SANG, Esq., F.R.S.E.*

The improvements about to be described have been applied to machines furnished with Macpherson's circular shuttle, and were, in fact, made while carrying that invention into practice; some of them are applicable to other machines. The first of these is

The Thread Stop.

A short time ago there was read to the Society a description of the circular shuttle invented by Mr Daniel Macpherson. By means of this shuttle the loop in the upper thread is drawn down and widened, the spool containing the under thread passed through the loop, and that loop retained until the next one be fairly taken hold of by the point of the shuttle. The widening of the second loop draws up and tightens the slack of the former one. The passage of the shuttle entirely through the loop, and the retention of that loop by a rigid metallic lip, form the distinctive characteristics of Mr Macpherson's invention, which leaves little or nothing to be desired in the manner of forming the stitch.

* Read before the Society, and machine with improvements exhibited, 25th February 1867. Awarded the Society's Silver Medal and Plate, value Five Sovereigns.

VOL. VII.

3 A

When this contrivance, accompanied by the usual arrangements for regulating the tension of the upper thread, was applied to actual work, it was found to answer admirably for a considerable variety of materials; but on other substances, and whenever there was any marked change in the thickness, it was found to be liable to the serious defect called looping; and when his additional improvement, whereby the chain-stitch is produced with the same shuttle, was tried, the tendency to loop was found to be greater. It became necessary to investigate the cause of, and to devise a remedy for, this very serious evil.

Let, in fig. 1, ABCDEFG represent the position of the upper thread when a loop is about to be drawn up; the end A being fastened into the cloth WW at the last completed

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stitch. The needle is supposed to have been thrust through the cloth at the point B, to have been withdrawn, leaving the loop BCD, through which the shuttle and spool with the under thread have passed; to have been again thrust through the cloth at E, and to have been withdrawn after the hook H has obtained hold of the second loop EFG. This hook or shuttle-toe H, in entering farther into the loop, draws it down, and as the end G of the thread is held back by the tension-wheel, it is expected that the widening of the loop at F should be accompanied by the drawing up and tightening of that at C.

Now, in order that this effect may be produced, a number of conditions must be fulfilled. In the first place, the upward motion of the thread at D is resisted by the hold which the cloth has upon it. If the material be non-elastic the

needle-hole remains open, and the thread passes easily through it; but when the material is elastic its parts close round the thread, and cause great resistance. Also, whatever the nature of the substance may be, the loop at C has to be drawn so tight as to imbed the under thread in the cloth. The strain requisite for this must be caused by a pull on the part EF, and that pull must be greater than the strain at C by the friction of the thread CDEF upon the cloth; and the tension on FG must be still greater by the friction of the thread against the steel toe H. Investigations as to the friction of ropes against rigid obstacles show that, for specified substances, and for a fixed angle of deflection, the tension at the one end bears to the tension at the other end a fixed ratio; and for ordinary sewing mate

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rial, experiments give for the ratio belonging to one half turn values from 2: 1 to 2: 1. I shall take for illustration the ratio 24: 1 or 9: 4. In this way, for every ounce of strain upon the thread at C we must have fully 24 ounces of tension at G; and thus it is that a slight increase of resistance at the point B requires such an augmentation of tension at G as to exceed that which the tension apparatus may be arranged to give, and may so cause the thread to be drawn from the reel rather than from the slack part at C, leaving therefore the loop hanging.

This investigation into the cause of looping explains how the matter becomes worse when the chain-stitch is to be worked. In this stitch the loop BCD is led round the two threads of the next loop EFG, and thus the angle of deflec

tion becomes three quarters of a turn. If the ratio for one half turn be 9: 4, that for one quarter must be 3: 2, and hence the ratio for three quarters of a turn becomes 27: 8 or 33: 1; that is, for each ounce of strain at the point C we must have 3 ounces of tension at G.

The cause of the looping being thus satisfactorily ascertained, it remained to discover a remedy for it. That remedy cannot be found in an augmentation of the permanent tension at G, because such an augmentation would cause the thread for the next stitch to be measured off in an extended state, and so the sewing would be tighter than the material could bear. It is necessary to leave the permanent tension unchanged, and to insure the drawing up of the loop by taking fast hold of the thread so long as that part of the operation lasts. If the drawing up of the loop, and the measuring off of the supply for the next stitch had been simultaneous, it would have been difficult to have remedied the defect; but it so happens that, in the action of the circular shuttle, these operations, though following closely upon each other, are successive, and hence the cure is attainable.

M

K

N

G

The arrangement is very simple. Upon the needle arm, and best concentric with it, is placed a lever IKL, the end I of which presses against a steel piece, over which the thread is passed, the pressure being given by means of a spring sufficiently strong to take firm hold of the thread. The other end or tail L of the lever is so placed as to come against a stud M fixed to the frame of the machine. By means of a regu lating screw the contact is adjusted to take place when the thread is about to be drawn off the reel. This contact lifts

Fig. 3.

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