Aapasthamba Sutra Tharpana vilakkam By Soma deva sarma 1956 edition. Now the edition will be available In Giri trading company and in Bhavani book centre station road west mambalam and in the Surabi publishers station road west mambalam chennai.The author has given in details all about amavasai tharpanam and mahalaya tharpanam. ON all the 24 hours on all days we should wear 2.25 meters length angavastram. now a days it is impossible for many people so we are wearing 3 poonals. one for brahmachari and two for grahastha and 3rd is we are wearing instead of 2 .25 metres angavasthram.The book nirnaya sindhu says If the kartha wants to do mahalayam on his father' s thithi he need not have to see thithi vaaram and nakshatram. To do mahalayam srardham you have to avoid fridays,prathamai ,shasti,ekadasi Birth star of the kartha and kartha's wife and the birth star of kartha's eldest son. Rohini ,revathy without vyathipatham,and makam without thriodasi.Widows and widowers without son and Bachelors may do on amavasya day the mahalaya srardham. kartha who is having son should not do mahalayam on amavasya day. On chadurdasi day Mahalaya srardham should be done only to those who died in accident on the spot itself, by taking poison,killed by weapons etc; and for his fore fathers you must do mahalayam on another day as their death was normal. Six sastrigals are required for mahalaya srardham.(1) Viswedevas (2)Pithru pithamahar prapita mahar (3)Mathru pithamahi prapithamahi (4)Mathamahan mathuhpithamahan mathuprapithamahan with their wives (5)Kaarunya pithrus (6) Maha vishnu. Viswedevar and maha vishnu should sit facing east. All others should sit facing north. Samaradhanai samayal; Sastrigals who are in the same kartha's gothram can sit as maha vishnu or as viswedevar. Required things; Betel leaves;betel nut;sandal paste; ellu (gingilly seed) Raw rice; thulasi;banana fruits ;dharbai; aasana palagai or thadukku; Dhakshinai;Brass plate (Thambaalam) panchathra uthurini;Brass sombu with water. Use plenty of water for tharpanam; 3 liters for one amavasai tharpanam. Dhakshinaayana punya kala tharpanam falls on 16-7-2010. this year. uthirayanam tharpanam falls on 15-1-2011 this year. to be continued.