19th century. Authors There are 470 poets known either by their proper names or by causal names deduced from their works. The authors are unidentified in the case of a hundred stanzas. The poets belonged to different parts of Tamil Nadu and to different professions. Some of them were very popular like Kabilar, Nakkirar and Avvaiyaar and some others are rarely remembered by their names. Yet a general harmony prevails throughout these eight anthologies. The tone and temper of the age is reflected in all their poems with a singular likeness. They were moulded according to certain literary conventions or traditions that prevailed in the Sangam age. Yet they reveal the individual genius of the poets who sang them. Examples The Sangam literature is categorized into two: love or inner (Akam) or public life or outer (Puram). A verse from the 69th poem of Akanaṉūṟu : "விண்பொரு நெடுவரை இயல் தேர் மோரியர் பொன் புனை திகிரி திரிதர குறைத்த அறை இறந்து அகன்றனர் ஆயினும், எனையதூஉம் நீடலர் வாழி தோழி!" The verse speaks about the elegant chariots on which the Mauryans rode through mountains and valleys and are referred to as "moriyar". These anthologies are significant source of cultural and historic information about ancient Tamil Nadu and South India. Akaval metre Of the eight anthologies five are on Agam, two on Puram, and one on both. Six of them are in 'agaval' metre which is a kind of verse, interspersed with alliterations and rhymes. The poems on Agam as well as Puram theme are written in this metre and its regulated and subtle music adds to the poetic beauty. This metre is a simple but wonderful instrument, which causes no impediment to the freedom of expression of the poet. It has been found to be an appropriate and natural medium for the expression of the valuable experience of the poets. Kali metres The other two anthologies that are not written in agaval metre are Kaliththogai and Paripaatal. The poems of Kaliththogai are in Kali metre which is known for its dramatic and lyrical qualities and which, according to Tolkappiyam is well suited to express the emotions of the lovers. There is repetition of certain lines and phrases and this, added to the haunting music of the metre, is very appealing. Paripaadal metre Paripaadal is a metre full of rhythm and music and the anthology known by this name consists of songs composed in this metre. There