212 
PROCEEDINGS OF THE ACADEMY OF 
this Academy, has recently removed his residence from the city or 
Philadelphia, and on that account has resigned his Curatorship, 
Resolved, That this Academy has accepted with sentiments of deep 
regret the resignation of Mr. Ashmead, one of the Curators of the So- 
ciety without intermission since 1841, a term of office rarely paralleled, 
and that it does hereby declare its high sense of his very valuable a*? 
well as long continued services. 
Resolved, That the thanks of this Academy be cordially tendered to 
Mr. Ashmead, and that the Corresponding Secretary be hereby in 
structed to furnish him with copies of these Resolutions. 
The following was adopted : 
Resolved, The the Committee on Proceedings be hereby authorized- 
to furnish to Mrs. Lucy W. Say, widow of the late Mr. Thomas Say, 
and herself a member of this Society, the Proceedings of this Academy 
gratuitously after January 1st, 1859. 
A resolution was also adopted giving to Mrs. Christiana Watson, 
widow of the late Gavin Watson, M.D., authority to issue orders and 
endorse tickets of admission to the Academy. 
Dec. 7 th. 
Vice President Lea in the Chair. 
Thirty-one members present. 
The following extract from a letter of Mr. C. 0. Sanford, dated Pe- 
tersburg, Ya., Oct. 20th, 1858; was read. 
I was much interested in the slab of sandstone (mentioned on page 177,) 
showing the ripple marks on its opposite sides, at right angles, or nearly so, and 
although I thought I could account for it, I was not willing to venture an 
opinion until I could have access to my books. 
I send an extract from Calver, on the improvement of tidal rivers, which sa- 
tisfies me that the marks were not made by currents, but by waves caused by 
winds. 
1st. A wind produced the ridges upon the soft bed of sand. 
2d. That a deposit of sand was made upon these ridges, which in like man- 
ner was ridged by a ^ind blowing at a different angle from the first. One side 
of the slab is probably the impression of the ridges first made. 
Extract from a letter loriiten by an officer in the British Navy. 
" In 1838, while lying in one of H. M. ships, in the port of Santander, on the 
north coast of Spain, we observed, upon looking over the side at high water. 
and when the water was unusually clear, that the bottom, composed of sand^ 
was covered by ridges running paratlel to the waves that had been on the sur- 
face during a strong breeze of two or three days' duration, but which had bean 
succeeded by a calm. Our anchorage was within the harbor, and the wind off 
shore. The impression it made on my mind at the time was, that as the ridges 
lay at right angles to the direction in which the wind had been blowing, thev 
were occasioned by a motion given to the water at that depth by the waves at 
the surface. 
Our anchorage at high water (the time alluded to,) was forty feet. 
I do not think that the waves, from the crest to the lowest part of the hollow 
could have been more than five feet, as the wind was an off shore one upon that 
coast. 
The ridges were small, apparently not more than a foot in width, and so, 
not corresponding in magnitude with the waves on the surface, but only with 
their direction." 
[Nov. 
