Chapter II

ON THE EQUATORIAL TELESCOPE, OR PORTABLE OBSERVATORY.

History of equatorials--Description of one of the simplest construction of these instruments--To adjust the equatorial for observation--To adjust the line of sight--Description of the _nonius_--To find the meridian line by one observation--Manner of observing stars and planets in the day-time

_page_ 453-464.

OBSERVATIONS, BY THE AUTHOR, ON THE FIXED STARS AND PLANETS, MADE IN THE DAY-TIME, BY THE EQUATORIAL.

Object of these observations--stars of the first and second magnitudes--General deductions from these observations

_page_ 464-469.

OBSERVATIONS ON THE PLANETS IN THE DAY-TIME.

Series of observations on _Venus_, when near the sun--Seen at the time of her superior conjunction in 1843--Conclusions deduced from these observations--phenomena observed during these observations--Remarkable phenomenon during an eclipse of the sun

_page_ 469-480.

OBSERVATIONS ON JUPITER AND OTHER PLANETS.

General conclusions, &c.

_page_ 480-485.

UTILITY OF CELESTIAL DAY OBSERVATIONS.

_page_ 485-491.

ON THE ASTRONOMICAL QUADRANT.

_page_ 492-496.

THE ASTRONOMICAL CIRCLE.

_page_ 496-502.

THE TRANSIT INSTRUMENT.

_page_ 502-505.

CHAPTER III.

ON OBSERVATORIES.

Leading features of a spot adapted for celestial observations--Public and private observatories--Greenwich observatory--Instruments with which an observatory should be furnished--The Author’s private observatory--Revolving domes for observatories--Cautions to be attended to in celestial observations

_page_ 506-516.

CHAPTER IV.

ON ORRERIES OR PLANETARIUMS.

History of such machines--Sphere of Archimedes and Posidonius--Dr. Long’s _Uranium_--Wheel-work of the common Planetarium--Figure representing this machine--Problems which may be performed by it

_page_ 517-527.

DR. HENDERSON’S PLANETARIUM.

Section of its wheel-work--Number of teeth in the wheels and pinions which move the different planets--Extreme accuracy of these movements. _page_ 527-538.

ON THE VARIOUS OPINIONS WHICH WERE ORIGINALLY FORMED OF SATURN’S RING, ILLUSTRATED WITH 13 VIEWS.

When and by whom its true figure was discovered.

_page_ 538-543.

ON THE SUPPOSED DIVISION OF THE EXTERIOR RING OF SATURN.

Kater’s, Short’s, Quetelet’s and Decuppis’s observations

_page_ 543-547.