420. The process employed in manufacturing often depends upon the mode in which a tax is levied on the materials, or on the article produced. W atch glasses are made in England by workmen who purchase from the glass house globes of five or six inches in diameter, out of which, by means of a piece of red-hot tobacco pipe, guided round a pattern watch glass placed on the globe, they crack five others: these are afterwards ground and smoothed on the edges. In the Tyrol the rough watch glasses are supplied at once from the glass house; the workman, applying a thick ring of cold glass to each globe as soon as it is blown, causes a piece, of the size of a watch glass, to be cracked out. The remaining portion of the globe is immediately broken, and returns to the melting pot. This process could not be adopted in England with the same economy, because the whole of the glass taken out of the pot is subject to the excise duty.
421. The objections thus stated as incidental to particular modes of taxation are not raised with a view to the removal of those particular taxes; their fitness or unfitness must be decided by a much wider enquiry, into which it is not the object of this volume to enter. Taxes are essential for the security both of liberty and property, and the evils which have been mentioned may be the least amongst those which might have been chosen. It is, however, important that the various effects of every tax should be studied, and that those should be adopted which, upon the whole, are found to give the least check to the productive industry of the country.
422. In enquiring into the effect produced, or to be apprehended from any particular mode of taxation, it is necessary to examine a little into the interests of the parties who approve of the plan in question, as well as of those who object to it. Instances have occurred where the persons paying a tax into the hands of government have themselves been adverse to any reduction. This happened in the case of one class of calico-printers, whose interest really was injured by a removal of the tax on the printing: they received from the manufacturers, payment for the duty, about two months before they were themselves called on to pay it to government; and the consequence was, that a considerable capital always remained in their hands. The evidence which states this circumstance is well calculated to promote a reasonable circumspection in such enquiries.