(April 16, 1885 Ė May 17, 1965), a member of the Yugantar group, revolutionaries led by Barindra. Barin and his friends had been experimenting with bombs since 1906. They made a technological leap when they were joined by Ullaskar Dutt, a dropout from Howrah who had taught himself chemistry after reading about the coming revolution in Jugantar. By October 1907 he was ready to make a bomb powerful enough to destroy a train. The group acquired some dynamite from a friend whose father owned a mine. Ullaskar loaded it into an iron cylinder and attached a detonator of his own manufacture. Learning that Fraser was planning to travel north from Calcutta on November 5, they went to a suitable spot on the railroad line to place the bomb, but the train rushed by before they could do so. Undeterred, they tried again ten days later when Fraser was scheduled to return. This time they laid the bomb in time, but the train did not come. Disappointed but still determined to kill Bengalís highest official, Barin and Ullaskar planned their next attempt in advance. The newspapers had reported that Fraser would return to Calcutta from the south in the first week of December. While Ullaskar was working on his biggest bomb yet, Prafulla Chaki and Bibhutibhusan Sarkar went to Narayangarh, near Midnapore, to dig a hole beneath the rails. After finishing the spade work, they returned to Calcutta and, on December 3, came back with Barin and the bomb. Placing it in the hole and setting the fuse, they waited for the train. It did not come. Prafulla and Bibhutibhusan dug up the bomb while Barin hurried back to Calcutta. He returned with a newspaper that said that Fraser would depart on the night of December 5. Going back to their hole, they again placed the bomb and then sat down to a meal of sweetmeats. Barin walked back to Narayangarh to catch the last regular train to Calcutta. When it passed the spot where Bibhuti and Prafulla were waiting, they set the fuse and started for home. A few hours later Fullerís special train passed over the bomb. It exploded deafeningly. The engine heaved upward, but the train did not derail. Climbing down, the lieutenant-governor surveyed the damage and ordered an investigation.
In January or February 1908, Ullaskar, Barin, and some others had gone to Deoghar. There Ullaskar succeeded in charging a shell with picric acid, and he and others went to an isolated spot to try it out. One of the group, Prafulla Chakravarty, was given the honor of throwing the bomb. It worked beautifully, but Prafulla and Ullaskar did not take cover quickly enough. Prafulla was killed on the spot, Ullaskar seriously wounded.
In the Alipore Bomb Case he was sentenced to be hanged by the neck until he is dead, but on appeal the sentence was reduced to transportation for life in the Andamans. There he was subjected to brutal torture in the Cellular Jail and is said have lost his mental balance. He was set free in 1920 and he returned to Calcutta.
Ulaskar was again arrested in 1931 and sentenced to 18 months imprisonment. He returned to his home village Kalikachha when colonial rule ended in 1947. After a lonely life of 10 years, he returned to Kolkata in 1957. After returning to Kolkata he married a physically challenged woman and went to Silchar, the district town of Cachar District of Assam and spent his later life there.
Ullaskar was normally fun-loving and light-hearted. He had a sweet singing voice and was a good ventriloquist and a caricaturist.