सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

84 nition of a yojana was given basing ultimately on the units of Angulas and yavas (grains of paddy) differently by differ- ent authorities, and in as much as the circumference of the earth’s globe was more or less unanimously accepted, he has chosen to define a yojana on the accepted measure of the circumference. In some other place Bhāskara says that a yojana is equal to 4 Krōsās, where the word Krōsa etymologically means that distance through which the topmost voice of a healthy person could be heard by another healthy person having good audition. In this context it may be recalled how Śrīpati defined a yojana under verses 69, 70 Madhyamādhyāya of his Sid- dhānta Śekhara. “The minute speck of dust that is seen flying in the light of the Sun’s rays entering a house through the windows, is called a paramāṇu (not an atom as is being translated now). Eight such paramāṇus equal one Reṇu. Eight Reṇus equal the breadth of the end of a hair known as Vālāgra or Kaccha-mukha or yūka. Eight Vālāgras equal one Likshā; Eight Likshās equal one Yava; eight Yavas equal one Angulā; twelve Angulās make what is called a Vitasti (i.e. the expanded length of a palm of the tallest person). Two Vitastis equal one Hāsta. Four has- tās make one Chāpa. Two thousand Chāpas make one Krōsa and four Krōsās are reported to be equal to a yojana by Astronomers” Verse 2. Rectification of the circumference .ie. find- ing the length of the circumference of the earth parallel to the terrestrial equator and passing through the locality in question. Also the definition of the primary meridian. The equatorial circumference of the earth multiplied by cos ϕ and divided by R or multiplied by 12 and divided by the hypotenuse of the right angled triangle formed by the gnomon and the equinoctial midday shadow thereof. (Hereafter called equinoctial hypotenuse) gives the circum- ference of the earth parallel to the equator and passing