rOL. XLVI.] PHILOSOPHICAL TRANSACTIONS. 33 



halfway towards the neck, when by pulling the tumour forwards, he had suffi- 

 cient room for tying a ligature round its basis, which was very broad. 



For the first 3 days after the operation, she complained of a good deal of pain 

 in the abdomen. On the 6th day the tumour dropped off. From the first of 

 the operation, she voided her urine without any assistance, and was afterwards 

 perfectly well in every respect. 



Remarks on the Solar and the Lunar Years, the Cycle of \g Years, commonly 

 called the Golden Number, the Epact, and a Method ofjinding the Time of 

 Easter, as it is now observed in most Parts of Europe. Being Part of a 

 Letter from the Right Honourable George Earl of Macclesfield.* N° 494, 

 p. 417. 



Of the Solar Year. — The mean tropical solar year, or that mean space of time 

 wherein the sun, or earth, after departing from any point of the ecliptic, returns 

 to the same again, consists, according to Dr. Halley's tables, of 365'* 5*^ 48™ 

 55': which is ll™ 5* less than the mean Julian year, consisting of 365'' 6^. 

 Hence the equinoxes and solstices anticipate, or come earlier than the Julian 

 account supposes them to do, by ll™ 5% in each mean Julian year; or 44"" 20' 

 in every 4 ; or 3** l*" 53™ 20* in every 400 Julian years. To correct this error 

 in the Julian year, the authors of the Gregorian method of regulating the year, 

 when they reformed the calendar in the beginning of Oct. 1 5, 1582, directed that 3 

 intercalary days should be omitted or dropped in every 400 years ; by reckoning 

 all those years whose date consists of a number of entire hundreds not divisible 

 by 4, such as 1700, 1800, 1900, 2100, &c. to be only common, and not bis> 

 sextile or leap years, as they would otherwise have been; and consequently 

 omitting the intercalary days, which, according to the Julian account, should 

 have been inserted in the month of February in those years. But at the same 

 time they ordered that every 400th year, consisting of a number of entire hun- 

 dreds, divisible by 4, such as 1600, 2000, 2400, 2800, &c. should still be 

 considered as bissextile or leap years, and of consequence that one day should be 

 intercalated as usual in those years. This correction however did not entirely 

 remove the error: for the equinoxes and solstices still anticipate l'' 53™ 20' in 

 every 400 Gregorian years. But that difference is so inconsiderable as not 

 to amount to 24 hours, or to one whole day, in less than 5082 Gregorian years. 

 Of the Lunar Year, Cycle of IQ Years, and the Epact. — The space of time 



* This nobleman had been a pupil of the celebrated Wm. Jones, Esq. vice-president of the Royal 

 Society, who was father of the no less celebrated Sir Wm. Jones, chief judge in India. Earl M. 

 was elected president of the Royal Society about the year 1751, on the resignation of Martin Folkes, 

 Esq. His lordship was greatly instrumental in procuring the introduction of the New or Gregorian 

 stile into use in this country, which took place in 1752. And he died ia the year 1764 . 



VOL. X. F 



