LE VERRIER.

ADAMS.



LIST OF ILLUSTRATIONS.

THE OBSERVATORY, GREENWICH.

PTOLEMY.

PTOLEMY'S PLANETARY SCHEME.

PTOLEMY'S THEORY OF THE MOVEMENT OF MARS.

THORN, FROM AN OLD PRINT.

COPERNICUS.

FRAUENBURG, FROM AN OLD PRINT.

EXPLANATION OF PLANETARY MOVEMENTS.

TYCHO BRAHE.

TYCHO'S CROSS STAFF.

TYCHO'S "NEW STAR" SEXTANT OF 1572.