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From these numbers we have the following conclusions:

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It has been mentioned that Dr Long, omitting the polar circles, found the ratio of land to water as 124 to 349, or 100 to 281; in the present case it comes out, under the same circumstances, as 100 to 270. This is not a greater difference than might be expected from the advance in geographical knowledge since the time of Senex; and it seems to relieve Dr Long from any suspicion of having neglected to take proper precautions in trying the experiment; but it must be acknowledged that the numbers just stated differ much from those which M. Malte Brun has assigned to the same portions of Geography (Eng. Trans. Edinb. 1822) Vol. 1. p. 159. His words are, "We have found, by a pretty exact computation, that the land in each hemisphere and the zone bears to the whole the following proportions:

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the Earth's surface. Whether his results are more to be depended upon than those which have been now obtained, must be left for others to decide; but there is a circumstance which seems to corroborate very strongly the dependence which may be placed on the present method, since there is a remarkable coincidence between the numbers, which were found from Mr Carey's globe-plates in 1823, and Mr Addison's in the more recent examination.

The proportionate quantity of land in the southern hemisphere was found in 1823 to be 69.58, which exceeds that which is now given by only 0.87. The extents of the continents, likewise, with the islands respectively belonging to them, came out as follows:

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As M. Malte Brun does not explain his method of computation for the several zones, no more can at present be said, in that respect, than is pointed out in the text: but it may be remarked that he is not correct in the quantity of land, which he has deduced from his own data 0.400+0.559+0.297 1.256 0.075+0.313 0.388 for the two hemispheres, = 0.129; 3 3 3 3

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but the fundamental decimals are parts of three different integers, and consequently the third of their sum will not give the true proportion of them when taken together, to the whole.

When it is recollected that these calculations were made from the works of two distinct geographers, the agreement is possibly as near as could be hoped for; but it is really closer than, at first sight, can appear; for some little variations were accidentally introduced by the first determinations not having been referred to, until the second had been completed. It was then found that Van Dieman's land had been weighed with New Holland in 1836, but that it had been taken with the other Asiatic islands in 1823. The interior of Africa is so imperfectly known, that in the last instance it was thought best to omit all attention to the inland lakes that were drawn upon this part of the plates, although they were cut out from the other quarters of the globe. This exception was not made in 1823, which will account for the somewhat smaller quantity which was then found for this continent. The difference in North America is to be attributed to the discoveries which have been made of late years, and the larger allowance which was in consequence assigned to the land within the North Polar Circle. The deficiency for South America is not great, but it was sufficient to make it desirable to ascertain, if possible, a cause by which it might be occasioned. The larger dimension of Mr Addison's plates afforded the means of cutting more deeply into the great rivers of this continent: and Mr Carey, having been consulted pointed out another probable source of variation in the outline of the eastern coast, which, in consequence of recent surveys, is not now laid down exactly as it was in 1823. It certainly is remarkable that the deficiency, which in this case amounts to 0.72, is very nearly the same as occurs for the whole southern hemisphere; and it may also be stated, that the land of the northern hemisphere came out in 1823 as 193.19, which is 4.02 less than is now assigned for it, while the quantity (as may be seen above) which was then found for North America was also less by 4.60.

As the force of the present argument depends upon the two trials being not only distant in time, but in every other respect independent of each other, it may not be superfluous to mention that the numbers were also deduced from them in two different ways. On Mr Carey's globe the gores are 20° wide, and they extend each from the æquator

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to the pole, so then the land being separated from the water, their ratio could immediately be found for each of the thirty-six parts, without any reduction for the different magnitudes of the several zones.

** The different portions of ink on the different parts of the paper may be thought to affect their weights. These are generally in larger quantities on the land than on the sea, but not always: there is uniformly a kind of shading, which extends to some distance from the several coasts, and when the interior of a country is little known, it is comparatively blank. There is reason also to believe, that when the ink is thoroughly dried, it adds very little to the weight. The difficulty of reducing the paper, at different times, with any certainty, to the same degree of dryness, prevents a direct trial of the alteration, which might be produced in printing, but workmen consider it to be very small. Two pieces as nearly as possible of the same size, having been cut out of the same gore, the one which was perfectly white weighed 8.2 grains, while the other which was covered with names weighed only 8.1. The difference must have been occasioned by some accidental circumstances; but the experiment, as far as it goes, will tend to shew that no sensible error was likely to be occasioned by the attempt not having been made to introduce an allowance for this particular.

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