[ 58 9 ] 
the port; at the lowed point, and immediately as it 
rofe again I took it at the higheft, and repeating the 
experiment in this manner, I at lad took a mean of 
all the obfervations for the true height of the water. 
But the medium of the lowed: and highed which 
immediately fucceeded each other feldom differed 
much from the medium of them all. The numbers 
on the pod by which the altitudes were taken, are at 
the diflance of 3 inches from each other as I obferved 
before. 5 November 16, 1761, 5 11 16P. M. I took 
the following obfervations of the altitude of the water 
by the fide of the pod 11, 12. 94., 134.. io, 124. 
9, 144-. 9, 124,. 94, 134., 1©, 13. 9, 14. 9, 13.. 
9, 14. 
The medium of all, which is n-JL. for the true 
altitude of the water. Mr. Mafon at the fame time 
by about as many obfervations found 1 1 T s __. 
Some times, when the rife and fall of the water 
was very quick, inffead of taking the more regular 
rife and fall of the water, which fucceed one another 
at. longer intervals, I took notice of every the lead: 
rife and fall, in which cafe I had an affidant to write 
them down as fad as I told him. As an example of 
this, $ December 2, n h 15™ A.M. by a mean of 
69 obfervations taken, in this manner, I found the 
altitude of the water to be 3 JL 5 _; and at ii h 21" 
A- M. by a mean of 52 obfervations taken at the 
more regular, riling .and fallings of the water, I .found • 
the altitude to bo 3 
I always looked at my watch before I began to 
note the height of the water, and looked at it again 
when I had dnifhed the experiment; the medium 
of the two times I fet down as the true time of the 
obfervatica. 
