Prof. Lovering on the American Prime Meridian. 193 
between Greenwich and Washington, or any other spot in Amer- 
ica, this error or uncertainty in regard to the breadth of the At- 
lantic ocean on which so much stress is laid, can produce no more 
derangement in a map of the whole or any part of the United 
States, than when we push a map from one side to the other of 
our table. If we desire to unite a map of the United States with 
a map of Europe so as to form a map of the world, then the un- 
certainty in question will manifest itself. But no alteration in 
our prime meridian from one place to another will remove or di- 
minish it; it is absolutely insurmountable. After we have made 
our map of the United States and drawn the meridians upon it, 
the selection of numbers to describe these meridians is a question 
of convenience rather than of scientific accuracy. If we count 
these meridians from Greenwich, the difference of two numbers 
will give the relative difference of longitude between the two 
meridians to which they are affixed. These differences will be 
permanent, though the absolute numbers may change by some 
constant quantity, and the differences as well as the absolute 
numbers may be placed upon our maps and charts if the conven- 
lence of those who use them requires it. 
I am not able to see that any other scientific operations will be 
materially affected by the substitution of an American prime me- 
ridian for that of Greenwich. I do not see that the details of the 
American Nautical Almanac or the calculations of those who use 
it, whether astronomers, navigators or engiveers, will be ensured 
any greater accuracy by the establishment of an American prime 
n 
meridian, 
extent, all our calculations for practical and scientific purposes, 
until either the uncertainty itself is removed, or we are prepared 
to make American science in spirit as wel] as in form, wholly in- 
dependent of those precious results which centuries of labor have 
garnered up at the venerable observatories of Europe. If we 
¥ i ated i 
I speak, though it does not 
ns. An astronomical epheme- 
long series of American observ- 
ations would, I doubt not, be better adapted to the wants of 
merican astronomers and serve more effectually the purposes of 
Serigs, Vol. IX, No. 26.—March, 1850. 25 
