" PHYSICAL ASTRONOMY. 149 
and Neptune with their moons, are habitable, are questions which must be 
left unanswered, as these planets, although little smaller than Saturn, are so 
remote as to render it impossible for us to ascertain the peculiarities of their 
physical condition by means of our telescopes. 
As it is hardly supposable that all the planets and moons revolve about 
the sun as uninhabited worlds, and that only the earth has the prerogative 
of being peopled with any kind of created beings, so it seems not impossible, 
yea, rather entirely suited to the omnipotence of the Deity, to assume a 
certain habitableness of the comets. Shall these heavenly bodies, which 
are by far the most numerous of all the worlds belonging to our solar 
system, and in proportion to which the numbers of primary and secondary 
planets vanish away—shall these be entirely uninhabited, simply because 
man cannot comprehend of what sort the beings dwelling on the comets 
must be? In fact, it is a sentiment completely recognising the all-wise 
beneficence of the Creator, to presuppose that, upon those worlds wandering 
through such an immense extent of the heavens, certain beings may exisi, 
as comfortable and happy as man, who so complacently considers himself as 
lord of the earth. 
The Calendar in General; the Greek, Julian, Gregorian, Russo-Grecian, 
Jewish, Turkish, and French Republican Calendars in particular. 
71. The Calendar belongs, from its nature and particular application, te 
the department of Chronology. Chronology, however, forms a part of 
astronomy, and, indeed, is a part of the greatest importance and most 
material value to the sciences, particularly the historical and political. For 
this reason it will not be superfluous to present here the most important 
features of the different calendars. 
72. Calendar means partly the division of time employed by any people 
into definite years, months, &c., and partly the register of single days 
answering to a certain year of such a division. The word calendar is 
derived from the Latin calende (xorew, Lat. calo, to call), by which name the 
Romans indicated the first day of every month, whose name and new moon 
were proclaimed by the priests, the calendar of any given year containing 
not only the religious and political festivals, but also the most important 
celestial events of that year. Among the latter are to be reckoned 
especially, the rise and setting of the sun and moon, the length of days and 
nights, the quarters of the moon, the eclipses of the sun and moon, the 
appearance of the planets, &c. We distinguish also, not only the calendars 
of different nations, but also special calendars, according to purport or 
object. Thus, for instance, we have astronomical, civic, centennial, 
economical, people, and states’ calendars. We shall. now hurry over the 
calendars of the most important nations in order. 
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