पञ्चसिद्धान्तिका (आचार्य वराहमिहिर - सूर्य, रोमक, पौलिश, वासिष्ठ एवं पितामह सिद्धान्त)

XIV.32 XIV. ASTRONOMICAL INSTRUMENTS 275
30. Dividing as in the case of tithi, find the local time in terms of ghaṭīs for the
end of full moon tithi (as reckoned from local sunset). Increase or diminish the
ghaṭīs obtained by the time corresponding to the Sun’s ascensional difference,
according as the Sun is the six signs beginning with Aries or in the six signs
beginning with Libra. The result is the local time for the end of the full moon
tithi at the local equatorial place. (The difference of this and the local time for
the end of the full moon tithi at Laṅkā) is the true longitude for the local place.
The rule is obvious, because: (a) Local time for the end of the full moon tithi at the local place (as
measured since sunset at the local place) ± time corresponding to the Sun’s ascensional differ-
ence = local time for the end of the full moon tithi at the local place (as measured since sunset at
the local equatorial place),

• − sign are to be taken according as the Sun is in the six signs beginning with Aries or in the six
  signs beginning with Libra.
  (b) Also, local time for the end of the full moon tithi at the local equatorial place ~ local time for
  the end of the full moon tithi at Laṅkā = local longitude in terms of time.
  The local time for the end of the full moon tithi at the local place has to be obtained by the process
  of successive approximations, but the whole process has not been described in the text.
  [नाडी (घटी) मानम्]
  द्युनिशिविनिःसृततोयादिष्टच्छिद्रेण षष्टिभागो यः ।
  सा नाडी (खम्थथो) वा श्वासाशीतिः शतं पुंसः ॥ ३१ ॥
  कुम्भार्धाकारं ताम्रं पात्रं कार्यं मूले छिद्रं
  स्वच्छे तोये कुण्डे न्यस्तं तस्मिन् पूर्णे नाडी स्यात् ।
  मूलाल्पत्वाद्वेधो वा षष्टियोर्ज्या चाह्ना रात्र्या
  वर्णाः षष्टिर्वक्राः श्लोको यत्तत् षष्ट्या वा सा स्यात् ॥ ३२ ॥
  8. The Nāḍī or Ghaṭī

31. One-sixtieth of the time taken by water to flow out through a desired hole
    during a nychthemeron is defined as the duration of a nāḍī. Or, it is the time
    of 180 breaths of a man.
    29a-b. B. देशाक्षतवशाक्षतपधेनोडुपतप्तरामिकर्मा; d. A.C.D. वियुतयुक्तं; B. विड्युत (B2. विधुत) युक्तं
    A. कृतवधेनोडुपूूर्णमाकर्म; D. कृतवेधेनोडुपपूर्णमाकर्म 30a. B. तिथिविभाज्यं D. विकृत्य
    c. B. देष्टि b. A. चकालादिनान्वितः; B. चकालदनान्वितं
    c-d. A.B. घटिकोदयांसंदुल्पान्यत्वे; (B. ०स तुल्यान्यत्वे); c. A.B. जूकादिषु पति हीनं
    C. घटिकान्तरांशानधिकल्पत्वे; d. B. विषुवती
    D. घटिकोदयांशतुल्यान्यत्वे