Davis’s Report on the Nautical Almanac. 327 
tothe Nautical Almanac to publish these positions in a suitable 
0) } ) 
corrections and additions of every successive year. In the par- 
ticular case of the coast survey these positions are determined 
_astronomically, geodetically, and by means of the electro-mag- 
netic telegraph. 
They comprise the light-houses, beacons, capes, headlands, 
shoals, points of entrance to harbors, &c., on the shores of the 
Atlantic, Pacific, and the Gulf of Mexico. They are indispens- 
able to the safety of the navigator and to the security of the 
property under his care; and being found in the pages of that 
work to which he resorts for the elements of his astronomical 
These positions also embrace in their number the most con- 
spicnous towns and trigonometrical stations with their magnetic 
? 
commission opens the almanac for the requisite astronomical data 
of his observations, hé may find also such terrestrial data as will 
answer for the proper basis of his field work, and, at the same 
time, as the standard of accuracy to his own independent compu- 
tations. To meet his wants, some additional constants will be 
pography, and the 
with the’ best and most 
s 
numerous list of American geographical positions extant 
“on of the observatories, are given in 
the British. ‘This, therefore, is regarded as another improvement 
in the American almanac upon the latter. : 
The other signal advantage spoken of, relates to the subject o 
Survey. But it is the province 
the results of these various labo 
the practical demands of navigation and engineering. We have 
hitherto been indebted to the observations and discussions made 
