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I should have given the preference to Murdoch's,
which deserves to be generally followed. The
scale of my map is 32 millimetres” for every de-
gree of the equator. The scale of increasing la-
titudes is not founded on the tables of Don Jorge
Juan, but on those which M. de Mendoza calcu-
lated for the spheroid.
To give a more suitable form to the map of
Mexico, the scale was only extended from the 15°
to the 41° of north latitude, and from the 96°
to the 117° of longitude. These limits did not
admit of giving in the same map the intendancy
of Merida or the peninsula of Yucatan, which
belongs to the kingdom of New Spain. To in-
clude in the map the most eastern point, which is
Cape Catoche, or rather the island Cozumel, seven
additional degrees of longitude are requisite, which
would have forced me to comprize in the same
map a portion of the kingdom of Guatimala, for
which I have no data, all Louisiana, all western
Florida, a part of the Tennessée, and of the Ohio.
It is in vain to seek, in this general map of New

Spain, the Spanish establishments on the north

west coast of America, establishments which are insulated, and may be considered as colonies dependant on the metropolis of Mexico. To exhibit in the same map the missions of New California would have required an additional eight degrees of

* 1.25987 In. English. Trans. WOL, I. C

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longitude; for the most-northern point of the
kingdom is the presidio of San Francisco, situated,
according to Vancouver, in 37°48'30% of north
latitude, and 124° 27' 45° of west longitude.
Hence a map of New Spain, to deserve the name
of a general map, should embrace the immense
countries included within the 89° and 125° of
longitude, and within the 15° and 38° of latitude.
To avoid the inconvenience of representing on a
large scale countries which, in a political view,
possess by no means the same interest, I wished to
compress my labour within narrower bounds. I
drew up, in a much smaller form, a second map,
which not only exhibits in a coup d'oeil all the
territories which depend on the viceroyalty of
Mexico, but which may also be consulted by those
who wish to examine the different communications
projected between the Atlantic ocean and the
South sea. The motives which have occasioned
this latter map to be extended to the port of Phi-
ladelphia, and even to the mouth of the Rio San
Juan at Choco, will be explained in the sequel of
this work.
Although, according to the principles often laid
down by me, I persist in preferring the new mea-
sures to the old, I have not however added to my
maps the scale of centesimal degrees. The Bureau
of Longitudes having constantly followed, both in
the Knowledge of Times (Connoissance des Temps)
and in the new Astronomical Tables lately pub-

--------- - - -—am-m-m-mool GEOGRAPHICAL INTRODUCTION. xix

lished, the old manner of computing the latitudes, a single individual would in vain oppose the torrent, in publishing latitudes expressed in centesimal parts. It is to be hoped, however, that the introduction of the metrical system, fixed by the arrété of the 13 Brumaire, year IX, will become gradually general. The degrees of longitude which I indicate are computed to the west of the meridian of the Imperial Observatory at Paris. If the great body of the public were not averse to even the most useful innovations, I should have preferred, to the meridian of Paris, the universal meridian proposed by one of the first geometricians of the age", founded on the movement of the great axis of the solar ellipsis. This universal meridian is 185° 30' to the east of Paris, which is 166° 46' 12" of the ancient sexagesimal division. It passes, consequently, by the South Sea, 12' to the east of the isle of Erromanga, which belongs to the archipelago of the Holy Ghost (du Saint Esprit). The introduction of a universal meridian, founded on nature itself, which would not shock the national vanity of Europeans, is so much the more to be desired, that we every day see augmented the number of first meridians arbitrarily traced on maps. Spain, for several years back, reckons five: Cadiz, the most in use with navigators; Carthagena; the new observatory at the isle of Leon; the college of Nobles at Madrid, introduced by the beautiful maps of M. Antillon; and the point de la Galera at the island of Trinidad. To these five meridians might be added other two which pass through the Spanish possessions, and have been adopted by a great number of geographers: I mean the meridian of Teneriffe and of the island of Fer. The latter occasions inevitable confusion, d’Anville placing it between the town of Fer and Cape West. So that there are seven first meridians, without reckoning Toledo, in the sole dominions of the king of Spain. I have followed, in the denomination of the seas which wash the coasts of Mexico, the ideas proposed by M. Fleurieu in his observations on the hydrographical division of the globe; a work in which the most enlarged views are united to a profound historical erudition. The Spanish names have often been added to facilitate the reading of travels written in Spanish. In drawing up the map of Mexico, I began by assembling together all the points fixed by astronomical observations, from which I formed a view, which, for the better appretiating the degree of confidence which the results deserve, indicates the nature of the observation and the name of the observer. The number of these points amounts to 74, of which 50 are situated in the interior of the country. Of this latter class there were only fifteen known before my arrival at Mexico in the month of April, 1803. It may be useful to discuss some of the thirty-three points whose position is determined by my own observations, and which are all comprised between the 16° 50' and 20° o' of latitude, and the 98° 29 and 103° 12 of longitude. While we are fixing these positions, we shall enter into some historical details respecting the extraordinary errors which have been propagated to this day in the most recent and current maps.

* Exposition du Systeme du Monde, par Laplace, p. 19.

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Several meridian altitudes of the sun and stars gave me for the latitude of the capital at the convent of St. Augustin", 9° 25'45". The longitude deduced from the eclipses of the satellites of Jupiter, from the distances from the moon to the sun, from transference of the time from Acapulco, and from a trigonometrical operation for estimating the difference of meridians between Mexico and the port of Vera Cruz, is 6° 45' 42" or 101° 25' 30". I shall observe once for all, that I rely on the numbers which result from the very careful calculations of M. Oltmanns, a distinguish

* The great gate of the cathedral church of Mexico is 12" farther north, and 10’’ farther east, than the convent of St. Augustin, near which I made my observations

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