LXXI. Odservations on the present State of Nautical Astro- 
nomy ; with Remarks on the Expediency of promoting a more 
gener al Acquaintance with the modern Improvements in the 
Science among the Seamen in the British Merchant Service. 
By Epwarp Rippwe, late Master of the Trinity- House 
School, Newcastle; now Master of the Upper School, Royal 
Naval " Asylum, Greenwich. 
I; there be any circumstance by which the present age is pre- 
eminently distinguished, it is the advantage with which the results 
of scientific inquiry have been applied in the practical concerns of 
life. This observation is applicable to almost every branch of 
philosophical investigation; but its truth is strikingly obvious 
with respect to the science of Astronomy. For though this sci- 
ence has been cultivated from the earliest times, it is not more 
than a century and a half since our countryman Newton first dis- 
covered its physical theory; and it is to the age in which we live 
that the honour belongs, not only of perfecting the science, but 
of bringing its most important practical applications within the 
reach of every one whom they are likely to benefit. 
We should mistake, however, if we imagined that the labours 
of all who had previously cultivated this science must have been 
utterly thrown away. ‘The diligence of observers had collected a 
mass of facts, which, long before the time of Newton, had given 
several sagacious individuals a pretty accurate conception of the 
proximate cause of the leading planetary phenomena; and which 
also furnished such data for the application of the Newtonian 
theory, such tests of its truth, and such materials for inrproving 
it, as modern observations could notin themselves have supplied. 
Now, though little confidence can be placed iu the individual 
accuracy of very ancient observations, they derive a real and im- 
portant value from a circumstance which gives to many useless 
objects an imaginary one; namely, their antiquity. Suppose, 
for example, an astronomer at the beginning of the Christian 
era should have erred six hours in stating the time at which he 
observed a total eclipse of the sun. If he were quite certain 
that during a period of the eclipse the darkness was total, his 
mistake respecting the time at which it happened, monstrous 
as it is in itself, would shrink into insignificance if his observa- 
tion were compared with the well determined time of a corre-' 
sponding modern eclipse, to discover the length of a mean luna- 
tion; as the resulting error would scarcely exceed a single se- 
cond of time. 
It is in this view chiefly that old astronomical observations are 
valuable ; for, down to a comparatively late period, when they 
are compared with each other, they are as discordant as the state 
- Vol. 58. No. 283. Nov. 1821, Ss of 
