While these pictures reveal Muybridge as a late-Romantic figure, his animal studies and spectacular multi-plate panoramas of San Francisco reveal a proto-Modernist, infatuated with science and the rapidly changing world. Even here, his aesthetic is apparent; each individual frame of, say, a greyhound running or an athlete somersaulting has an independent beauty. Devoid of narrative, displaying a concern more for formal concepts and design, they share many of the traits of the art of the second half of the following century — except they are more beautiful than much of it.

Muybridge died in 1904, four years after the portraitist Alice Neel was born. Neel herself died in 1984 after a life as eventful as Muybridge's and so forms a bridge between his world and our own. 

Never one of the most lauded American artists, she was nevertheless a significant figure who worked quietly as Abstract Expressionism, Pop Art and Minimalism eddied around her. Rarely seen in this country, some 60 paintings from her long career are currently on show in Alice Neel: Painted Truths at the Whitechapel Gallery (until September 17). 

In the 1950s, an FBI investigation labelled her a "romantic bohemian-type communist" but her subjects fit no one class or political persuasion. They encompass lovers and strangers, rich and poor, union men and museum men, those she liked and those she clearly didn't, and above all family and friends. 

In pictures of bright colour, she concentrates solely on the figure, often leaving backgrounds barely realised as a statement that her interest is solely in her sitter or, since she liked to paint twins, sitters.

Hers are odd portraits. There is no great refinement of technique and her colouring and drawing are frequently clumsy. They are, though, beguiling because they have a certain home-spun mundanity; these are pictures about personality and not status or self-image. There is nothing mundane about the strength of Neel's gaze, nor her willingness to wait until her sitters dropped any pretence and revealed in their faces "what the world had done to them".