In the fine arts, and in the arts of industry, as well as in the pursuits of science, the highest department of each is that of the discovery of principles, and the invention of methods. To investigate the laws by which human intellect picks with caution its uncertain track through those obscure and outlying regions of our knowledge which separate the known and the certain from the unknown;—to teach us how to cast as it were an intellectual and temporary connecting line across that chasm, by which a new truth is separated from the old—confident that when arrested by that isolated truth it will have fixed itself upon one solid point, amidst a floating chaos of error,—confident also that, when once the fixity of that single point has been assured, it is always _possible_, however formidable the task, to link it by innumerable ties to established knowledge, and thus to fill up the intervening space even to the very boundary of its enlarged domain:—to achieve such a conquest in any science surpasses all other discoveries, for it supplies tools for the use of intellect, and enlarges the limits and the powers of human reason. § One of the great advantages of the Exposition will arise from the interchange of kindly feelings between the inhabitants of foreign countries and our own. The classes who visit us will consist neither of the very elevated nor of the very low. They will all of them, probably, possess more instruction and information than the average of their class amongst their countrymen: consequently they will consist of persons the most likely to derive instruction from their visit, and therefore to return home with pleasing impressions. It has been found on the continent that the periodic unions of men of science have had an excellent effect in removing jealousies and establishing friendships. It has not unfrequently happened that two philosophers have met in such societies, and have entered into discussions which have enabled each to appreciate more justly the talent of the other, before one of them was aware that he had formerly criticised a work of his new friend, in terms which their present good understanding would effectually prevent him from repeating. The experience we have had of the visit of the National Guard of Paris, strongly confirms this view. It brought out the better feelings of our nature towards our neighbours, and all classes took their share in endeavouring to make those visits agreeable. On their return home, the feeling excited by the visit was conveyed far beyond the actual visitors; and it has left on the population of Paris a permanent advance in good will towards Englishmen.