It has frequently been regarded as a subject of discouraging consideration, that whilst purely literary products of intellectual activity are rooted in the depths of feeling, and interwoven with the creative force of imagination, all works treating of empirical knowledge, and of the connection of natural phenomena and physical laws, are subject to the most marked modifications of form in the lapse of short periods of time, both by the improvement in the instruments used, and by the consequent expansion of the field of view opened to rational observation, and that those scientific works which have, to use a common expression, become antiquated by the acquisition of new funds of knowledge, are thus continually being consigned to oblivion as unreadable. However discouraging such a prospect must be, no one who is animated by a genuine love of nature, and by a sense of the dignity attached to its study, can view with regret anything which promises future additions and a greater degree of perfection to general knowledge. Many important branches of knowledge have been based upon a solid foundation which will not easily be shaken, both as regards the phenomena in the regions of space and on the earth; whilst there are other portions of science in which general views will undoubtedly take the place of merely special; where new forces will be discovered and new substances will be made known, and where those which are now considered as simple will be decomposed. I would therefore venture to hope that an attempt to delineate nature in all its vivid animation and exalted grandeur, and to trace the stable amid the vacillating, ever-recurring alternation of physical metamorphoses, will not be wholly disregarded even at a future age.

Potsdam, Nov. 1844

The results of the study of physical phenomena

The different epochs of the contemplation of the external world ...
The different degrees of enjoyment presented by the contemplation

of nature

Instances of this species of enjoyment

Means by which it is induced......

The elevations and climatic relations of many of the most celebrated
mountains in the world, considered with reference to the effect
produced on the mind of the observer

2

8

4

6-12

13

.........

The impressions awakened by the aspect of tropical regions
The more accurate knowledge of the physical forces of the universe.
acquired by the inhabitants of a small section of the tempe-
rate zone

The earliest dawn of the science of the Cosmos

The difficulties that opposed the progress of inquiry
Consideration of the effect produced on the mind by the observa-
tion of nature, and the fear entertained by some of its injurious
influence

Illustrations of the manner in which many recent discoveries have
tended to remove the groundless fears entertained regarding
the agency of certain natural phenomena...

The amount of scientific knowledge required to enter on the consi-
deration of physical phenomena.............

The object held in view by the present work
The nature of the study of the Cosmos......
The special requirements of the present age

.....

Page

Limits and method of exposition of the physical description of the

The natural philosophy of the ancients directed more to celestial