Equinoctial Regions of America, vol 1 | Page 6

of
transparency of the air on the brinks of the craters of Pichincha and
Jorullo; they also contain topographical plans and geological profiles of
these mountains, founded in part on the measure of vertical bases, and
on angles of altitude. Each observation has been calculated according to
the tables and the methods which are considered most exact in the
present state of our knowledge; and in order to judge of the degree of
confidence which the results may claim, we have preserved the whole
detail of our partial operations.
It would have been possible to blend these different materials in a work
devoted wholly to the description of the volcanoes of Peru and New
Spain. Had I given the physical description of a single province, I could
have treated separately everything relating to its geography, mineralogy,
and botany; but how could I interrupt the narrative of a journey, a
disquisition on the manners of a people, or the great phenomena of
nature, by an enumeration of the productions of the country, the
description of new species of animals and plants, or the detail of
astronomical observations. Had I adopted a mode of composition which
would have included in one and the same chapter all that has been
observed on one particular point of the globe, I should have prepared a
work of cumbrous length, and devoid of that clearness which arises in a
great measure from the methodical distribution of matter.
Notwithstanding the efforts I have made to avoid, in this narrative, the
errors I had to dread, I feel conscious that I have not always succeeded
in separating the observations of detail from those general results which
interest every enlightened mind. These results comprise in one view the
climate and its influence on organized beings, the aspect of the country,

varied according to the nature of the soil and its vegetable covering, the
direction of the mountains and rivers which separate races of men as
well as tribes of plants; and finally, the modifications observable in the
condition of people living in different latitudes, and in circumstances
more or less favourable to the development of their faculties. I do not
fear having too much enlarged on objects so worthy of attention: one of
the noblest characteristics which distinguish modern civilization from
that of remoter times is, that it has enlarged the mass of our conceptions,
rendered us more capable of perceiving the connection between the
physical and intellectual world, and thrown a more general interest over
objects which heretofore occupied only a few scientific men, because
those objects were contemplated separately, and from a narrower point
of view.
As it is probable that these volumes will obtain the attention of a
greater number of readers than the detail of my observations merely
scientific, or my researches on the population, the commerce, and the
mines of New Spain, I may be permitted here to enumerate all the
works which I have hitherto published conjointly with M. Bonpland.
When several works are interwoven in some sort with each other, it
may perhaps be interesting to the reader to know the sources whence he
may obtain more circumstantial information.
1.I.1. ASTRONOMICAL OBSERVATIONS, TRIGONOMETRICAL
OPERATIONS, AND BAROMETRICAL MEASUREMENTS MADE
DURING THE COURSE OF A JOURNEY TO THE EQUINOCTIAL
REGIONS OF THE NEW CONTINENT, FROM 1799 TO 1804.
This work, to which are added historical researches on the position of
several points important to navigators, contains, first, the original
observations which I made from the twelfth degree of southern to the
forty-first degree of northern latitude; the transits of the sun and stars
over the meridian; distances of the moon from the sun and the stars;
occultations of the satellites; eclipses of the sun and moon; transits of
Mercury over the disc of the sun; azimuths; circum-meridian altitudes
of the moon, to determine the longitude by the differences of
declination; researches on the relative intensity of the light of the
austral stars; geodesical measures, etc. Secondly, a treatise on the
astronomical refractions in the torrid zone, considered as the effect of
the decrement of caloric in the strata of the air; thirdly, the barometric

measurement of the Cordillera of the Andes, of Mexico, of the province
of Venezuela, of the kingdom of Quito, and of New Grenada; followed
by geological observations, and containing the indication of four
hundred and fifty-three heights, calculated according to the method of
M. Laplace, and the new co-efficient of M. Ramond; fourthly, a table
of near seven hundred geographical positions on the New Continent;
two hundred and thirty-five of which have been determined by my own
observations, according to the three co-ordinates of longitude, latitude,
and height.
1.I.2. EQUINOCTIAL PLANTS COLLECTED IN MEXICO, IN THE
ISLAND OF CUBA, IN THE PROVINCES OF CARACAS,
CUMANA, AND BARCELONA, ON THE ANDES OF NEW