in favour of his son Otto
Struve, born at Dorpat in 1819. He died November 23, 1864.

An inquiry into the laws of stellar distribution, undertaken during the
early years of his residence at Pulkowa, led Struve to confirm in the
main the inferences arrived at by Herschel as to the construction of the
heavens. According to his view, the appearance known as the Milky Way is
produced by a collection of irregularly condensed star-clusters, within
which the sun is somewhat eccentrically placed. The nebulous ring which
thus integrates the light of countless worlds was supposed by him to be
made up of stars scattered over a bent or "broken plane," or to lie in
two planes slightly inclined to each other, our system occupying a
position near their intersection.[108] He further attempted to show that
the limits of this vast assemblage must remain for ever shrouded from
human discernment, owing to the gradual extinction of light in its
passage through space,[109] and sought to confer upon this celebrated
hypothesis a definiteness and certainty far beyond the aspirations of
its earlier advocates, Cheseaux and Olbers; but arbitrary assumptions
vitiated his reasonings on this, as well as on some other points.[110]

In his special line as a celestial explorer of the most comprehensive
type, Sir William Herschel had but one legitimate successor, and that
successor was his son. John Frederick William Herschel was born at
Slough, March 17, 1792, graduated with the highest honours from St.
John's College, Cambridge, in 1813, and entered upon legal studies with
a view to being called to the Bar. But his share in an early compact
with Peacock and Babbage, "to do their best to leave the world wiser
than they found it," was not thus to be fulfilled. The acquaintance of
Dr. Wollaston decided his scientific vocation. Already, in 1816, we find
him reviewing some of his father's double stars; and he completed in
1820 the 18-inch speculum which was to be the chief instrument of his
investigations. Soon afterwards, he undertook, in conjunction with Mr.
(later Sir James) South, a series of observations, issuing in the
presentation to the Royal Society of a paper[111] containing
micrometrical measurements of 380 binary stars, by which the elder
Herschel's inferences of orbital motion were, in many cases, strikingly
confirmed. A star in the Northern Crown, for instance (Eta Coronae),
had completed more than one entire circuit since its first discovery;