Surya Siddhanta
छेद्यकम् लिखता भूमौ फलके वा विपश्चिता । विपर्ययो दिशाम् कार्यः पूर्वापरकपालयोः॥
By the wise man who draws the projection (chedyaka), upon the ground or upon a board, a reversal of directions is to be made in the eastern and western hemispheres. [This verse is inserted here in order to remove the objection that, in the eastern hemisphere, indeed, all takes place as stated, but, if the eclipse oc- curs west of the meridian, the stated directions require to be all of them reversed. In order to understand this objection, we must take notice of the origin and literal meaning of the Sanskrit words which designate the cardinal directions. The face of the observer is supposed always to be east- ward: then " east " is prdfic, " forward, toward the front "; " west " is pagcdt, " backward, toward the rear "; " south " is dakshina, " on the right "; " north " is uttara, " upward " (i.e., probably, toward the mountains, or up the course of the rivers in north-western India). These words apply, then, in etymological strictness, only when one is looking eastward and so, in the present case, only when the eclipse is taking place in the eastern hemisphere, and the projector is watching it from the west side of his projection, with the latter before him: if, on the other hand, he re- moves to B, turning his face westward, and comparing the phenomena as they occur in the western hemisphere with his delineation of them, then " forward " (prdftc) is no longer east, but west; " right " (dakshina) is no longer south, but north, etc. It is unnecessary to point out that this objection is one of the most frivolous and hair-splitting character, and its removal by the text a waste of trouble: the terms in question have fully acquired in the language an absoluto meaning, as indicating directions in space, without regard to the position of the observer.]
english translation
chedyakam likhatA bhUmau phalake vA vipazcitA । viparyayo dizAm kAryaH pUrvAparakapAlayoH॥
hk transliteration by Sanscript