It is evident, therefore, that a man who possesses a good trade as a coachmaker has little inducement to embark in the perilous field of invention. His time is mostly taken up with his ordinary business, and unless under very peculiar circumstances he has little or no time to study improvements. Those who have too little business to fill up their time are interested in producing new things in order to attract public attention. First ideas very often originate with mechanics and artisans, who have not the means of putting them into practice, unless in comparatively trifling improvements. Established tradesmen generally consider it their interest to discourage such things, as interfering with their plans and giving them more trouble without extra profit. Thus, when under-springs were first adapted to carriages, it was prophesied that they would be the ruin of the coach-making trade, by making carriages too durable. When the streets were Macadamised, wheelwrights and coachmakers alike complained that it was destruction to their trade. It is the same in other things. The Manchester cotton-spinner, who has a mill and machinery already erected, does not feel very benevolently disposed towards an inventor who contrives new machinery of a better class, by which he can underwork him and take away his trade. It may be taken as a general rule that new inventions are viewed with jealousy by all established tradesmen, on the ground that they are an individual advantage, and not in the outset advantageous to the trade in general. Therefore, they keep them down all in their power, and when they succeed it is by the circumstance that they are valuable in themselves, and that the customers of the tradesmen insist on having them.