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

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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