by a _clavecin oculaire_, or
ocular harpsichord; but the treatise and the illustration were quickly
forgotten. He also wrote _Mathematique universelle_ (1728) and _Traite
de physique sur la pesanteur universelle des corps_ (1724). He also
published a critical account of the system of Sir Isaac Newton in French
in 1743.

CASTELAR Y RIPOLL, EMILIO (1832-1899), Spanish statesman, was born at
Cadiz on the 8th of September 1832. At the age of seven he lost his
father, who had taken an active part in the progressist agitations
during the reign of Ferdinand VII., and had passed several years as an
exile in England. He attended a grammar-school at Sax. In 1848 he began
to study law in Madrid, but soon elected to compete for admittance at
the school of philosophy and letters, where he took the degree of doctor
in 1853. He was an obscure republican student when the Spanish
revolutionary movement of 1854 took place, and the young liberals and
democrats of that epoch decided to hold a meeting in the largest theatre
of the capital. On that occasion Castelar delivered his maiden speech,
which at once placed him in the van of the advanced politicians of the
reign of Queen Isabella. From that moment he took an active part in
politics, radical journalism, literary and historical pursuits. Castelar
was compromised in the first rising of June 1866, which was concerted by
Marshal Prim, and crushed, after much bloodshed, in the streets by
Marshals O'Donnell and Serrano. A court-martial condemned him _in
contumaciam_ to death by "garote vil," and he had to hide in the house
of a friend until he escaped to France. There he lived two years until
the successful revolution of 1868 allowed him to return and enter the
Cortes for the first time--as deputy for Saragossa. At the same time he
resumed the professorship of history at the Madrid university. Castelar
soon became famous by his rhetorical speeches in the Constituent Cortes
of 1869, where he led the republican minority in advocating a federal
republic as the logical outcome of the recent revolution. He thus gave
much trouble to men like Serrano, Topete and Prim, who had never
harboured the idea of drifting into advanced democracy, and who had each
his own scheme for re-establishing the monarchy with certain
constitutional restrictions. Hence arose Castelar's constant and
vigorous criticisms of the successive plans mooted to place a
Hohenzollern, a Portuguese, the duke of Montpensier, E