time, might have been stripped, while being handed down by oral tradition, of those grammatical forms which in the course of time had become obsolete, but which, if once recognised and sanctioned in theological seminaries, would have been preserved there with the most religious care. According to Dr. Haug, the period during which the Vedic hymns were composed extends from 1400 to 2000 B.C. The oldest hymns, however, and the sacrificial formulas he would place between 2000 and 2400 B.C. This period, corresponding to what has been called the _K_handas and Mantra periods, would be succeeded by the Brâhma_n_a period, and Dr. Haug would place the bulk of the Brâhma_n_as, all written in prose, between 1400 and 1200 B.C. He does not attribute much weight to the distinction made by the Brahmans themselves between revealed and profane literature, and would place the Sûtras almost contemporaneous with the Brâhma_n_as. The only fixed point from which he starts in his chronological arrangement is the date implied by the position of the solstitial points mentioned in a little treatise, the _G_yotisha, a date which has been accurately fixed by the Rev. E. Main at 1186 B.C.[43] Dr. Haug fully admits that such an observation was an absolute necessity for the Brahmans in regulating their calendar: 'The proper time [he writes] of commencing and ending their sacrifices, principally the so-called Sattras or sacrificial sessions, could not be known without an accurate knowledge of the time of the sun's northern and southern progress. The knowledge of the calendar forms such an essential part of the ritual, that many important conditions of the latter cannot be carried out without the former. The sacrifices are allowed to commence only at certain lucky constellations, and in certain months. So, for instance, as a rule, no great sacrifice can commence during the sun's southern progress; for this is regarded up to the present day as an unlucky period by the Brahmans, in which even to die is believed to be a misfortune. The great sacrifices generally take place in spring in the months of _K_aitra and Vai_s_âkha (April and May). The Sattras, which lasted for one year, were, as one may learn from a careful perusal of the fourth book of the Aitareya-brâhma_n_a, nothing but an imitation of the sun's yearly course. They were divided into two distinct parts, each consisting of six months of thirty days each; in the midst of both was the Vishuvat, i. e. equator or central day, cutting the whole Sattra into two halves. The ceremonies were in both halves exactly the same, but they were in the latter half performed in an inverted order.' [Footnote 43: See preface to the fourth volume of my edition of the Rig-veda.]