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ed simultaneously at Greenwich and Paris, 1020 24' 15"; and by eight satellites compared with the corrected tables, 102° 15' 47"; the mean term of which is 102° 19' 8", the longitude adopted by M. Antillon in the analysis of the map of America. There were observed besides during the stay of Malaspina's expedition at Acapulco, in 1791, two stellar eclipses, for which there were however no corresponding observations in Europe. Captain Don Juan Tiscar calculated them from the tables of Bürg. He found Acapulco, by the eclipse of the 19th February, 102° 9' 45", and by the eclipse of the 15th April, 102° 35' 45". Distances of the moon from the sun, taken the 12th February, but calculated by groups, and without correct. ing the situation of the moon by the observation of a passage to the meridian, gave 102° 24' 37".

Here are a great number of determinations by very different means! All of them give a longitude somewhat more western than the result of my own observations, which I adopted before I had any knowledge of the interesting memoir of M. Espinosa. Stellar eclipses are certainly preferable to every other species of observation, if they are conducted under favourable circumstances. But the results of the eclipses of the two stars observed at Acapulco differ from one another, according to the calculation of M. Tiscar, 26', and according to M. Oltmanns in an arc of 5'. The Spanish astronomers admit a very great error of the tables

VOL. I.

for the first satellite. They make it 35" in time, while M. Oltmanns, on comparing the tables of Delambre with observations from the month of January to the month of May 1791, finds the error of the tables only —7", 6 for the immersions, and - 14" for the emersions. He believes, agreeably to the calculations published in thu second volume of our collection of astronomical observations, that the true mean term of the observations of Malaspina's expedition is 102° 14' 30", and that by merely allowing half the value to our observations, we might fix the longitude of Acapulco at 102° g' 39": that is to say, that it would be three minutes and a half further west than is indicated in my map. We ought not to be astonished at these doubts which remain as to the position of a port of the South Sea, when we consider that the longitude of Amsterdam was uncertain till a few years ago, not for three or four minutes, but the third part of a degree.

XII. MAP OF THE DIFFERENT ROUTES BY WHICH THE PRECIOUS METALS FLOW FROM ONE CONTINENT INTO THE OTHER.

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The quantity of gold and silver annually sent by the New Continent into Europe amounts to more than nine-tenths of the produce of the whole mines in the known world. The Spanish colonies, for example, furnish annually three millions and a half of marcs of silver *, while in the whole of the European states, including Asiatic Russia, the total annual produce of the mines scarcely exceeds † the sum of three hundred thousand marcs 1. A long stay in Spanish Ame. rica enabled me to procure more exact information with respect to the metallic wealth of Mexico, Peru, New Grenada, and the viceroyalty of Buenos Ayres, than is to be found in the works of Adam Smith, Robertson, or Raynal. From thence I might naturally have entered into an investigation of the accumulation of the precious metals in the south and south-east of Asia ; but a problem so important as this may constitute the subject of a particular memoir. I have thought proper to exhibit here the principal results of my researches, in a small map sketched at sea in 1804, on my passage from Philadelphia to France. This map indicates the fux and reflux of the precious metals. We observe in general that they move from west to east; a motion the reverse of that of the ocean, atmosphere, and the civilization of our species !

* 2,370,046 Troy pounds. Trans.

+ See, as to the mines of Europe, the excellent statistical table of the produce of mines, annexed to the Memoire general sur les Mines, par M. Heron de Villefosse, p. 249. (Paris 1809, chez Fr. Schoell.) 1 203,130 pounds Troy. Trans.

XIII. FIGURES REPRESENTING THE SURFACE OF NEW SPAIN, AND OF ITS INTENDANCIES, THE PROGRESS OF MINING, AND OTHER OBJECTS RELATIVE TO THE EUROPEAN CO. LONIES IN THE TWO INDIES.

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The collected figures in this plate serve to ex. plain what is afterwards said * on the extraordinary disproportion between the extent of the colonies and the surface (area) of the European mother countries. The inequality of the territorial division of New Spain has been rendered sen. sible in representing the intendancies by squares inscribed above one another. This graphical method is analogous to what M. Playfair first employed, in a very ingenious manner, in his commercial and political atlas, and in his statistical maps of Europe. Without attaching much importance to these sketches, I cannot regard them as mere trifles foreign to science. It is true the map which M. Playfair gives of the national debt of England brings to mind the section of the Pic of Teneriffe; but natural philosophers have long indicated by similar figures the state of the barometer and mean temperature of months. It would be ridiculous to endeavour to express by curves, moral ideas, the prosperity of nations, or decay of their

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* Chap. i. and chap. viii.

literature; but whatever relates to extent and quantity may be represented by geometrical figures; and statistical projections which speak to the senses without fatiguing the mind, possess the advantage of fixing the attention on a great number of important facts.

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