So the notion of these four ages may be best remembered by a deteriorating series expressed by a descending arithmetical progression as 4, 3, 2, 1, by the conversion of units into thousands and by the legend that these are divine years each composed of 360 years of men. A period of 4,320,000 years constitutes a great age, or a Mahayuga, and this number multiplied by 1,000 i.e., 4,320,000,000 years becomes a day of Brahma :—
Daivikanam Yuganam tu sahasram parisamkhyaya | Brahmam-ekamaharjneyam tavati | ratrir-eva cha. At the end of this day a dissolution of the universe will occur, when all the three worlds, earth and the regions of space will all be consumed by fire. The three worlds then become but one mighty ocean. Brahma will sleep for a night, of equal duration with his day, on this ocean and at its close will create the world anew. A year of Brahma is composed of 360 such days and nights and a hundred such years constitute his whole life, which is called a Kalpa. Brahmanaschayusha Kalpa kalpavidbhih nirupitah. Such, in brief, is the belief of the Hindus regarding the ages and the duration of the
