Sitbnicrgciicc in the Narragaiisctt Bay. — Fuller. 3 1 3 
present sea level. It should be noticed that these figures 
represent a minimum subsidence, being based on the figures 
given by Dana — the foremost advocate of a slight Champlain 
subsidence in southern New England. Even this amount, 
however, could l)e made to meet, to a considerable extent, the 
requirements demanded by the sand-plains described by 
Woodworth. 
Competejicy of Outlets. — The level of the ocean at the 
time of the deposition of the sand-plains being, as held by 
Woodworth, approximately as at present, an increase in the 
hight of the waters of the upper part of the bay could only 
take place v^'hen the capacity of the outlets to the ocean was 
less than the capacity of the combined glacial streams entering 
at the same time. It is my object to show that, in all prob- 
ability, there were no floods of sufficient magnitude to cause 
more than a very slight rise, and certainly none sufficient to 
account for the rise of fifty feet demanded. 
()n Mr. Woodworth 's map of the glacial deposits in the 
vicinity of Narragansett bay he gives, in addition to the higher 
plains laid down in water held up by local topographic con- 
ditions, eight plains with crests from forty to sixty feet eleva- 
tion above tide. They are distributed from the vicinity of 
Wickford Junction on the south to Harrington on the north. 
In most of these plains the evidence as to the nature and 
size of the streams by which they were laid down is unsatis- 
factory, but the Harrington plain, which is one of the largest, 
has been shown to have been deposited by a single stream 
having a width, as indicated V)\ its esker. not exceeding 150 
feet. Our knowledge of the size of glacial streams in Alaska 
and Greenland leads to the belief that the depth of the water 
in such a stream could not have exceeded twenty feet. In 
order not to under-rate the imj)ortance of the stream, how- 
ever, I have, in calculating the area of its cross section, 
assumed that it had a width, not of 150 feet, but of 200 feet, 
and a depth, not of twenty feet, but of fift\ feet. The area 
of the cross section of such a stream, it will be seen, is 10,000 
scjuare feet. 
There are three outlets to the sea from the up])er Nar- 
ragansett bay. one on each side of the Conanicut island, and 
a third between Aquidneck, or Rhode island, and the main- 
