To form an accurate idea of this operation, it is necessary to see a Brabant Thread-spinner at her work. She carefully examines every thread, watching it closely as she draws it off the distaff; and that she may see it the more distinctly, a piece of dark blue paper is used as a background for the flax. Whenever the spinner notices the least unevenness, she stops the evolution of her wheel, breaks off the faulty piece of flax, and then resumes her spinning. This fine flax being as costly as gold, the pieces thus broken off are carefully laid aside to be used in other ways. All this could never be done by machinery. It is different in the spinning of cotton, silk, or wool, in which the original threads are almost all of uniform thickness. The invention of the English flax-spinning machine, therefore, can never supersede the work of the Belgian fine thread spinners, any more than the bobbinnet machine can rival the fingers of the Brussels lace-makers, or render their delicate work superfluous. The prices current of the Brabant spinners usually include a list of various sorts of thread suited to lace-making, varying from 60 francs to 1800 francs per pound. Instances have occurred, in which as much as 10,000 francs have been paid for a pound of this fine yarn. So high a price has never been attained by the best spun silk; though a pound of silk, in its raw condition, is incomparably more valuable than a pound of flax. In like manner, a pound of iron may, by dint of human labor and ingenuity, be rendered more valuable than a pound of gold.