326 
[Assembly 
are spread out in sheets which are waved on their upper surface, an ap- 
pearance communicated by the shght ripple of the water from which the 
deposit took place. In these masses we find many cavities, and with 
fine yellow crystals. In fine, the caves of Watertown are well worth 
the attention of the traveller. 
The following report has been furnished by professor F. N. Bene- 
dict, of the University of Vermont. It will, I have no doubt, be con- 
sidered an important addition to the information which has already been 
communicated through the Legislature to the people. 
It beais upon the face of it great accuracy, and a patient investigation of 
the subjects upon which it treats. It will be perceived that it gives an 
impartial view of the measurements of the mountains of the northern 
section of the State, and places in their true light the relative value of the 
barometrical and trigonometrical measurements in general. In relation to 
the discrepancies which appear between us I would remark, 1st, that 
Professor Benedict's instruments are more perfect than those I used. In 
the 2d place, we have invariably found that the greatest differences ap- 
pear with Burlington as a station than with those at Albany, N. Y. 
which seems to result from the difference of time in the changes of at- 
mospheric pressure. It is proper also to add that the observations 
made upon White-Face, in 1837, by myself and Mr. Hall, were at a 
time the most unfavorable for accuracy, being made at or nea.r the time 
of the autumnal equinox, and just at the commencement of a storm ; a 
a time when the fluctuations of the barometer are greater than at 
other periods. I have not at any time claimed a greater [accuracy in 
measurement than my observations would warrant. It has been my 
wish that they should be received as approximations to the truth, hop- 
ing also that the attention of the public might be called thereby to the 
subject, that individuals might be induced to take it up and furnish a por- 
tion of the materials for a final result ; for it is certain that the work of 
determining the height of the mountains, even of Essex county, is too 
great to be accomplished by one individual during the period of the 
survey. 
''Burlington, 13 Feb. 1840. 
To Prof. E. Emmons. 
Dear Sir — Agreeably with your request I visited at two dif- 
ferent times, in the months of July and August last, the sources of the 
Hudson, Saranac and Racket rivers, with the view of determining the 
