Helen Graham (The Tenant of Wildfell Hall) Helen Graham (The Tenant of Wildfell Hall) Helen Lawrence (married name is Helen Huntingdon but she is most commonly known under her alias Helen Graham) is the main female protagonist of Anne Brontë's 1848 novel "The Tenant of Wildfell Hall". Helen was portrayed by Janet Munro in the 1968 TV adaptation and Tara FitzGerald in the 1996 miniseries. Helen Lawrence was born in 1802 (or in the first half of 1803) at Wildfell Hall. Rachel, later her maid and friend, takes care of infant Helen. Her mother dies when Helen is still too young to remember her. Immediately after that,
19th century in science later in the 19th century by the German mathematician Bernhard Riemann; here no parallel can be found and the angles in a triangle add up to more than 180°. Riemann also developed Riemannian geometry, which unifies and vastly generalizes the three types of geometry. The 19th century saw the beginning of a great deal of abstract algebra. Hermann Grassmann in Germany gave a first version of vector spaces, William Rowan Hamilton in Ireland developed noncommutative algebra. The British mathematician George Boole devised an algebra that soon evolved into what is now called Boolean algebra, in which the only numbers were