74 JOURNAL OF THE 
val of the fittest is announced. Thunder is the rushing to- 
gether of several clouds ‘‘driven by warring winds.”’ 
The nature of clouds he discusses at greatlength. Some 
of these phenomena have puzzled men all through the 
ages and it is not nccessary to point ont how imperfect 
our knowledge still 1s. ) 
The interior of the earth is constituted as the surface 
and hence contains caves. lakes etc. Ihe falling in 
of such caverned depths cause the earthquakes. In these* 
caverns the air in motion ‘‘makes glow the rocks around.”’ 
Winged flames then ‘‘vomit from wide open jaws’’ hurl 
rocks, and send out cinders and smoke, and so volcanoes 
are formed. ~The constancy of the volume of the sea was 
observed by Lucretius and correctly accounted for. 
A strangely mistaken observation as to the temperature 
of wells is mentioned and of course his theory is made to 
cover and explain it. Such waters were thought to be 
cold in summer and warmin winter. This was, of course 
because what we mav call the personal thermometer reg- 
istered largely the relation to the temperature of the 
atmosphere. 
I have not been able to exhaust all of the observations 
recorded by this early philosopher, nor to properly 
show his ingenuity in fitting his theory as to atoms and 
the ‘‘seeds of things’’ to every case. Nor has it been 
possible to give a just idea of the grace and poetic beauty 
of this the first and only attempt to bring all of natural 
science within the limits of a single poem. 
WORKS CONSULTED IN THE PREPARATION OF THIS ARTICLE. 
1 TT. Lucretii Cari, De rerum natura, ex editione Gibb., Wakefieldi, 
Valpey’s auctores classici. 
2 Lucretius, On the Nature of Things. <A philosophical poem, trans- 
lated by Rev. John L. Watson, with the metrical version by John 
M. Good. 
