On Kirkwood’s law of therotation of the Primary Planets. 217 
globe. For whilst one extremity of this band is marked by the 
eruptions of Ischia and Vesuvius, where volcanic action has pre- 
vailed in the historical period, we have only to follow such zone 
from Naples to the N.N.W. to see that it passes along a portion 
of the Papal States replete with earlier volcanos, and is directly 
coincident with tracts powerfully affected in much more remote 
periods, along one of which volcanic action is still partially devel- 
oped in the hot vapor issues of the Tuscan Maremma. 
Arr. XXV.—On Kirkwood’s Law of the rotation of the Primary 
Planets ; by Ex1as Loomis, Professor of Mathematics and Nat- 
ural Philosophy in the University of the City of New York. 
Messrs. Editors,—In the last number of the American Journal 
of Science, in noticing a small volume of mine lately published, 
under the title of “ The recent progress of Astronomy, especially 
in the United States,” you say, “ One omission should be noticed. 
We do not find in this volume any allusion to Kirkwood’s cele- 
and distances from the sun. Ina history of American Astronomy 
especially, this discovery is entitled to an honorable mention.” 
As the enquiry has been made from a great variety of sources, 
why I have omitted in my book to make any mention of Kirk- 
ae discovery, I seem called upon to assign a reason for this 
ect, 
aes have swelled-the volume much beyond its present size. 
; hose topics have been selected in which it was supposed the pub- 
“ senerally would feel the deepest interest.” 
omitting to mention even the names of many professors of as- 
limits of the United States ; but the importance of Kirkwood’s 
: x recent progress of astronomy, especially in the United States. 
: m therefore forced to confess that my reason for omitting to 
Ptice Kirkwood’s law “was that I was not satisfied of its truth. 
Rie Pe made this public confession, I am bound to give my rea- 
“8 tor withholding my assent to the law. 
BOND Sutes, Vol, XI, No, 32.— March, 1851. 23 
