Night and day 1964 is one of Calder's many sculptures with moving elements, better known as 'mobiles', a term coined by Marcel Duchamp (1887-1968) and adopted by Calder to describe all such works.1 The first mobiles to hang from the ceiling (as does Night and day) appeared in about 1934, although relatively few were made until after the 1940s.
'I have chiefly limited myself to the use of black and white as being the most disparate colors. Red is the color most opposed to these, and then, finally, the other primaries.'2 This statement by Calder on his use of colour virtually describes Night and day, a mobile with numerous horizontal red disks and two vertical disks opposite each other — one black, one white — which undoubtedly prompted the title of the work. It is interesting to note that at the time Night and day was made, Calder was preparing his autobiography. On 6 April 1965 he recalled work he had done for the stage set of Henri Pichette's play Nucléa, presented in Paris in 1952. In the first section, devoted to war, two large panels, 'the clouds', descended from above and rotated alternately, displaying white and black sides: 'I will always remember the lines: "Nuit et jour" and "Jour et nuit"'.3
Michael Lloyd & Michael Desmond European and American Paintings and Sculptures 1870-1970 in the Australian National Gallery 1992 p.338.