188 On the Great Comet of 1843. 
Hitchcock as to the littoral nature of the footstep deposit in Con- 
necticut, and that the prints in question were left by birds on 
the mud and sand of former estuaries, the bottoms of which were 
gradually submerged, and by the increase of fresh matter were 
permanently preserved.” 
We are forced to omit an interesting page on the Dinornis of 
Prof. Owen, for want of room. Mr. M. continues: “Now to apply 
this discovery to our Ornithichnites, one of the greatest difficul- 
ties which many of us had to overcome, was the gigantic size of 
the largest American footsteps, which measure fifteen inches in 
length ; and it is a most curious fact that upon placing the fossil 
east alongside of the metatarsal bone and tibia of the largest 
individual of Dinornis, Prof. Owen is of opinion, that if the feet 
of this great tridactyle bird be found, they will, from the usual 
proportions maintained in such animals, be fully as large as those 
of the American Ornithichnite. From this moment, then, I am 
prepared to admit the value of the reasoning of Dr. Hitchcock, 
and of the original discoverer, Dr. James Deane, who, it appears 
by the clear and modest paper lately brought before us by Dr. 
Mantell, was the first person who called the Professor’s attention 
to the phenomenon, expressing then his own belief, from what he 
saw in existing nature, that the footmarks were made by birds. 
Let us now hope, therefore, that the last vestiges of doubt may 
be removed by the discovery of the bones of some fossil Dinor- 
nis ; and in the mean time let us honor the great moral courage 
exhibited by Prof. Hitchcock, in throwing down his opinions be- 
fore an incredulous public.” gon 
Arr. XXI.—On the Great Comet of 1843; by Mr. S.C. Waux- 
eR and Prof. E, O. Kenpaui, of Philadelphia.* 
High School Observatory, Philadelphia, May, 1843. 
To rue SECRETARIES oF THE AMERICAN PuiLosopntcaL SocreTy, &e. 
Gentlemen—We avail ourselves of the centennial meeting of 
the members of this Society to lay before them generally, the rea- 
sons which induce us to believe that the recent visitor is a com 
ot oh >, gece 
. * The first letter was communicated to the American Philosophical Society, at 
their centennial anniversary, May, 1843; and published in the United States Ga- 
zette, May 29,1843: since revised, and furnished by the authors, for this Journal, 
at the request of the Editors. The second letter is now for the first time published. 
