We are now replacing the thick by a thin spindle. It is true that with the slightest interference or rough handling, this thin spindle bends and begins to wobble. But it makes the movement of the wheel very smooth and easy, and also adds to its speed, as the revolutions are doubled from the fifty of the thick spindle to a hundred in the thin spindle following from one revolution of the large wheel. The doubling of revolutions does not mean a double output, but there is certainly a considerable increase. With the thick spindle, the wheel must go through 8 or 10 revolutions for the drawing and winding of one length of yarn; with the thin spindle, the revolutions of the wheel needed for that purpose are reduced to 4 or 5. Hence with the thin spindle, there is an economy of labour. The speed of drawing the yarn by the hand is clearly limited, so that 200 or 300 revolutions of the spindle instead of 100 would not double or treble the speed or the output. Advanced students draw and wind two feet to two feet and a half of yarn every five seconds. This comes to 8 to 10 yards a minute. If the sliver is good and the student in a spinning-mood, there is less breakage of yarn. Even considering the time lost on account of breakage and joining, some students are easily able to spin 400 to 500 yards of yarn of about 12 counts, fit for warp. This approximates to the speed of a mill spindle, and is therefore quite satisfactory. When the work is over, the student removes the spindle from the wheel and keeps it in good preservation. Yet accidents do occur. The class master must know how to repair a spindle which has thus gone wrong. He must also know how to put the wheel in good working order. The string which makes the spindle revolve often breaks, but if it is well-twisted, treated with wax, and then rubbed well with a piece of cloth, it becomes more durable and lasts for a number of days.