268 HISTORICAL VIEW OP THE

former, Flamstead anil Halley, in the latter, La Hireand Cassini, are at the head of long lists of illustriousnames who have fully evinced the wisdom of nationalliberality in the maintenance of these important insti-tutions. If there be in the British empire any esta-blishment, in the conduct and success of which thenation has reason to boast, it is the Royal Observatory.In spite of a climate which so continually tries thepatience, and so often disappoints the hopes of theastronomer, this single observatory has furnished alonger continued series of observations, upon a system-atic plan, and those more completely to be relied on,than all the rest of Europe together. Its determina-tions have afforded the data for the extensive researches,and the nicest tests for the theory, of physical astrono-my ; and have furnished the basis for the computationof those elaborate tables, by which the mathematiciansof Europe have expressed with such surprising accuracythe past, the present, and the future condition of theheavens, and which, in their highest degree of refinedaccuracy, are essentially necessary to the commonestoperations of navigation.

Figure and Magnitude of the Earth .

We have before noticed the rude attempts made bythe ancients towards determining the magnitude of theearth ; attempts characteristic of the genius of ancientscience. The mathematical principle on which theywere founded was perfect and exact, and is, in fact, thesame as that now adopted: but how to apply the prin-ciple practically, was a point of very secondary consi-deration with them. Habituated to the abstractions otpure geometry, the problem was considered solved if itcould be shown that we had the power of solving it;but the actual and practical exhibition of the result wasof inferior moment. The slowness with which the artof observation was matured, and the great distance atwhich it kept behind theory, is a remarkable fact in the