VOL. LXXX.J PHILOSOPHICAL TRANSACTIONS. 745 



in passing each sign, and they are accordingly longer in the apogee, and shorter 

 in the perigee; that which corresponds with the higher apsis being 31** 14^ 39"*, 

 and that with the lower 29** 8^ 21"^ only. It does not appear that the Hindoos 

 are accustomed to enumerate, for civil purposes, the days of the solar month, 

 but to date from the age of the moon that happens to fall within that month, or 

 frequently from the simple phase of the moon. 



Their festivals and fasts, like those of the Jews and Christians, being regu- 

 lated, for the most part, by the lunar revolutions, they employ on this account, 

 exclusively of the solar astronomical reckoning, a lunar year. This they make 

 to consist of 12 months, and each semi-lunation is distinguished into 15 equal 

 portions, or lunar days, which are somewhat shorter than the natural day. In 

 order to preserve its general correspondence with the solar year, " they reckon 

 twice that lunation during which the sun does not enter on any new sign,** or, 

 in other words, which falls completely within a solar month ; and the obvious 

 reason for this mode of intercalating is, that as the lunar months take their de- 

 nomination from the solar month in which the change happens, if 2 new moons 

 fall within the same month, they naturally take the same name, and no irregu- 

 larity is observable. This opportunity of increasing the number of lunar months, 

 without embarrassing the reckoning, presents itself, on a medium of a few years, 

 just as often as is requisite to effect the compensation. It cannot happen in all 

 the solar months indifferently, their lengths being unequal, and some of them 

 shorter than the synodical lunar month. 



The commencement of the solar day is usually estimated from sunrise, and the 

 space between that and the sunrise of the following day is divided into 60 parts, 

 the length of which must vary with the sun's unequal course through the ecliptic; 

 but for the purposes of calculation it is supposed to be ascertained at the solstices, 

 and is equal to 24 of our minutes. The subdivisions, in like manner, follow thS 

 sexagesimal scale. There is also a mechanical division of the day and night into 

 8 parts, of which 4 are allowed to the interval from sunrise to sunset, and 4 to 

 that from sunset to sunrise. The proportion of length of these parts respectively 

 depends therefore on the season of the year and the latitude of the place, and 

 the division is consequently inapplicable to general astronomy. 



The days of the week are denominated from the 7 planets, and their arrange- 

 ment is the same with that adopted in the western parts of the world, proceeding 

 from the sun and moon to Mars, Mercury, Jupiter, Venus, and Saturn. Friday, 

 or the day of Venus, appears as the first of the week in their calculations, and 

 probably because the Kalee Yoog began on that day; but in common the week 

 is considered by the Hindoos as beginning with Sunday. Having thus briefly 

 -touched on such points of their astronomy as are immediately connected with the 



VOL. XVI. 5 C 



