Davis’s Report on the Nautical Almanac. 323 
- where. And the proof of this is at hand. Whilst the lunar ta- 
bles were in the course of preparation, the Department, in a let- 
ter dated August 5, 1850, authorized the superintendent of the 
Nautical Almanac to publish his predictions and elements of the 
total eclipse of the following year, July 28, 1851, for the express 
purpose of testing the accuracy of the new tables, and of ac- 
uiring the means of further improvements; and on the 25th of 
August, 1850, the superintendent, by permission of the Depart- 
ment, communicated the predictions of his office to the American 
association for the advancement of science at that time in session 
at New Haven; he, at the same time, announced to the mathe- 
matical and physical section of that body, the preparation of the 
new lunar tables, and submitted to its criticism and approval the 
objects in view, and the mode in which they were to be accom- 
plished. His communication is contained in the printed proceed- 
ings of the association at that meeting. 
The event proved highly satisfactory, by showing conclusively 
the superiority of the lunar tables now in use in the office of the 
American almanac. ; 
For the prediction at Cambridge the British almanac was in 
error eighty-five seconds, and the American almanac only twenty 
sconds, 
_At Washington, the British almanac was in error for the be- 
ginning of the eclipse seventy-eight seconds, and for the end 
sixty-two seconds. The American almanac was in error for the 
beginning only thirteen seconds, and for the end only one second 
and a half. 
ing and decisive as to the superiority of our own lunar tables. 
The same tables of the moon’are used in the French and Berlin 
almanacs as in the British; the errors, therefore, are the same. 
The errors exposed in this eclipse may give rise to an error of 
that amount. The possibility of such an error, arising from this 
Source, is removed in the American ephemeris. 
added that calculations of certain ocenltations have been made at 
the office of the Nautical Almanac, for the sake of ascertaining 
Opportune occurrence 0 , ‘ 
tal eclipse of the sun, visible in some of its various phases through- 
