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the 1908 almanacs nearly seven hundred as-
teroids are included. The computation of
their perturbations and ephemerides by Eu-
ler’s and Lagrange’s method of variable el-
ements became so laborious that Encke de-
vised a special process for these, which can
be applied to many other disturbed orbits.
[8]
When a photograph is taken of a region
543