184 Bond, Graham, and Peirce, on the Latitude of Cambridge. 
of two and a half feet radius. They are published in the first 
volume of the Transactions of this Society, and agree together 
quite creditably to the observer. They give for the latitude of 
the observatory 42° 23’ 52” N. : 
Mr. Paine’s 584 observations of the latitude of Boston, made, 
in 1828 and 1829, with two of Ramsden’s sextants (the results 
of the two different instruments agreeing to the tenth of a second), 
and published in the first volume of the new series of the Trans- 
actions, give for the latitude of the Observatory * 42° 22’ 22”.3 N. 
Mr. Paine’s more recent observations of the latitude of Boston, 
made for the survey of the State and published in the Memoirs 
of the American Philosophical Society, give for the latitude of the 
Observatory * 42° 22’ 47.2 N. 
Mr. Paine’s observations of the latitude of the Unitarian Church 
in Old Cambridge give for the latitude of the Observatory * 42° 
22’ 46".7 N. 
The latitude resulting from the series of observations contained 
in this memoir is 42° 22’ 49” N. 
The agreement of the observations with each other, no one of 
which differs from the mean more than three seconds, shows that 
this latitude may be depended upon as accurate to about a sec- 
ond. Had simultaneous observations of the stars employed been 
made at Greenwich, or some other established observatory, the 
resulting latitude might have been depended upon to one half or 
one third of a second; and it is probable that, under favorable cir- 
cumstances, this system of observation will give differences of lati- 
* The differences of latitude necessary for these reductions were obtained 
from Mr. Charles O. Boutelle, who has made some careful trigonometrical 
observations of these differences of latitude, and has kindly communicated 
to the Observatory a copy of his results. 
