heavily filled as to prevent them from performing the office for which they are intended.

It is generally admitted that stronger yarn is made by the single than the double process. Such a result may possibly be due to the lesser number of teeth which act upon the fibres of cotton in the single than in the double process. The number of teeth which act upon a fibre in its passage through the card does not depend on the amount carded in pounds, but upon the area of carding-surface, and the number of times that the fibres pass by it. Increasing the number of teeth doubtless increases the breaking and tearing of the fibres, as well as elongates their natural spirals. The fibres are probably elongated in the carding process much as a shaving is lengthened by pulling on its two ends; in which operation we do not reduce the number of twists in the entire shaving, but we do reduce the number per inch. Many who admit that single-carded yarn is stronger than double-carded, will still say that the latter will run better in the weaving-room. I am not aware that experiments have been made in which all disturbing causes have been removed, so as to conclusively settle this question of strength.

Better mixing of staple is secured by the double than the single process; and it is not a sufficient answer to the objection to single carding, on this account, to say that the required mixing can be secured at the drawing-frame, or at the picker: the real question is, what is the best that can be done by the cards?

A probable greater uniformity of linear weight of sliver from the railway-head can be secured by the double than by the single system; for although, as has been previously stated, a less number of strands will usually be united in the former than in the latter process, it is probable that the advantages of using a lap on the finisher cards made from a large number of breaker card-slivers, will over-balance the advantages resulting from more strands in the railway-trough.

The fibres will be passed between a greater number of teeth in double than in single carding, and reducing the amount put through the card will not offset the advantage gained by increasing the carding-surface. The double system affords an opportunity not offered by the single system for correcting imperfections in the work which arise from faults in the condition. of the cards. More strippings will be made on the double than the single process; but the former system divides the waste into

Trains, one of which may in many cases be reworked, and The other out in sold, so that the net loss from waste on the 78 Sans Fil not materially differ.

The arantages of the double system appear to outweigh Use of Un sight 17 to the point where the amount of work Det at få fact a much exceeds seventy-five pounds: it then becomes, in tractocult to unite a sufficient number of ends in ale Tall Wa¬¬bead to secure efficient action of the evener without morvasing a ther the weight of the railway-sliver, or the speed of the bills all ve the limits usually fixed for producing good

Silstartily the same limit is fixed by the capacity of The common thx inch card to do satisfactory work, and 12 this card it would probably be better, as a choice of evils, To put tog pounds & day through each machine and card but OPOL, TET DET That one tandred pounds through each and repeat

When the Bockle process can be adopted without increasing the work for each and much above seventy-five pounds per day, #should be used; but when the work much exceeds that A generally be better to adopt the single system, and dalle the aim it into two lots, and allow each card to do the best it can with its own portion. Single carding may also be infially used in small mills where the number of cards employed is not sent to divide conveniently into breakers and finishers and make a good lap from the former, and where the small tumber et cards used allows each one to be constantly under the eye of a responsible person, who is interested to keep it in therergh enter: but it can be advantageously used in large mills only when by adopting the double process the quantity of work required for each card will be greater than the cards and their accompanying railway-heads can

handle well.

The limit at which it is advisable to abandon the double system is rarely reached on ordinary thirty-six inch top-flat cards, but it is soon passed on roller, combination, or under-flat cards, and the advantages of the double system are probably not sufficient to prevent the adoption of such cards if they shall show themselves capable of otherwise doing large amounts of work satisfactorily.

DRAUGHT IN CARDS.

No such law as that which limits the amount of draught between the rolls of a drawing or spinning frame prevents the employment of large draughts on cards. Drawing between rolls is an unevening process; we employ it as the best known means of reducing the size of the sliver, and of getting the fibres straight and parallel. The sliver produced by drawingrolls can be more uniform in size than that with which the rolls are supplied only when doubling occurs in connection with the drawing. Experience has shown that large draughts between rolls are impracticable on account of this tendency to unevenness; but the only limit to the amount of draught on cards is that which is fixed on one side by the weight of the lap that can be advantageously used, and on the other by the weight of the sliver that can be conveniently handled.

Picker-laps vary from about eight to fourteen ounces per yard, and the slivers, from doffers, from forty to one hundred grains per yard, with occasional exceptions on either side. The heavier lap, if made into the lighter sliver, would require a draught of one hundred and fifty-three, and the lighter lap, if made into the heavier sliver, a draught of thirty-five.

It is claimed that a thick lap fed slowly is better than a thin lap fed rapidly, because the fibres in a thick lap will receive a greater number of blows from the teeth in the cylinder than those in a thin sheet; but the weight of the lap is limited by the capacity of the perforated cylinders of the picker to collect an even sheet, and by the capacity of the feed-rolls of the card to so hold the lap as to prevent its being drawn into the card in bunches. The most common weight of picker-lap is about ten ounces per yard. The draught on cards, when united by railways, chiefly depends on the number that are so united. On breaker cards it is generally about equal to the doublings; but the weight of lap made at the lap-head is somewhat lighter than the picker-lap, on account of the strippings, &c., in the card.

On single carding, and on finisher cards used in double carding, the draught further depends on the weight of sliver which it is desired to make at the railway-heads. With a nine-ounce lap and a draught of seventy-eight on the card, the sliver will weigh forty-eight grains per yard, and this, with ten cards united in a section, and a draught of four and one-half in the

railway-head, will give a railway-sliver weighing about one hundred and six grains per yard. Other things being equal, a large draught on the card requires a high speed of doffer, and produces a light sliver from the doffer.

The carding action between the cylinder and doffer is doubtless more efficient with a light than with a heavy sliver; but with short-stapled cotton, the sheet will not hold together if greatly reduced in weight. A high speed of doffer makes a correspondingly high speed of railway-rolls necessary, but here, also, a high speed is better than a heavy sliver. It is probably better to run the front rolls of railway-heads five hundred revolutions per minute with a sliver weighing one hundred grains per yard, than to run them at four hundred revolutions with a sliver weighing one hundred and twenty-five grains per yard.

SPEED OF CYLINDERS.

The surface speed of a card-cylinder, thirty-six inches in diameter, when making one hundred and thirty revolutions per minute, is about twelve hundred feet, and of a cylinder fortyfive inches in diameter, when making one hundred and forty revolutions, about sixteen hundred feet. The former speed is most usual in this country, and the latter in England. These speeds are about forty times as great as those of the doffers: hence it follows that the gauzy film which envelops the under side of the doffer, is about forty times as heavy as that which is removed from the cylinder. When, therefore, the sliver from the doffer weighs forty grains per yard, that from the cylinder cannot much exceed one grain per yard. This film is so light that the difference in the appearance of the cylinder before and after it has taken its load at the feed-rolls is scarcely perceptible. The quantity of work done by the cards depends entirely on the weight of the lap and the speed of the feedrolls. It in no way depends on the speed of the cylinder or of

the doffer.

The cylinder carries the load from one side of the card to the other in a thinner or thicker sheet, depending on its speed; but the amount delivered by it to the doffer per minute is independent of its speed. Changing the speed of the cylinder will change the thickness of the load, but it will not change the number of teeth between which a given fibre of cotton will

pass, while going from one side of the card to the other. The speed of the cylinder should evidently be sufficiently high to so reduce the thickness of the film which it carries that every fibre shall, while passing through the card, be exposed to the action of the teeth; but, when this has been accomplished, there is probably little advantage, so far as the action of the teeth is concerned, in still further increasing the speed.

The centrifugal force, which tends to throw heavy foreign matter into the flats, increases with the speed; but the higher the speed of the cylinder, the greater will be the tendency of its clothing to bulge out, when running, and come in contact with that of the tops; the greater will be the amount of flyings at the ends of, and beneath, the cylinder; the greater the gatherings between the tops when they are raised for stripping; the greater the power required; and the greater the evils resulting from imperfectly balanced cylinders.

Experiments which have been made with thirty-six inch cylinders, running faster than one hundred and thirty revolutions per minute, have, so far as I know, failed to show any gain in the quality of the work, sufficient to compensate for the disadvantages attending the increased speed.

He would be a rash man who should appear in this place, to speak on the subject of carding, expecting to agree in every respect with all who were present. If I have succeeded in so presenting the subject as to secure an expression of their opinions from the members of the Association, I shall have performed the part assigned me by the Board of Government.

Mr. SAWYER. Professor Whitaker has prepared a series of charts which represent the various steps of flat carding, which he is ready to present to the Association, if they desire to have him do so.

A vote was passed requesting Professor Whitaker to exhibit his charts at this point, and they were shown by him accordingly.

Professor WHITAKER also read a paper on the subject, prefacing it as follows:

What I shall have to say will have to do with some progressive steps in the invention and improvement of the flat card; and, if it is in order, I should like, not to take a comprehensive and world-wide view of the subject, but simply to state some