corridors, which also stagger back in, in a sequence matching the front setbacks. The first three sections each bend slightly away from each other towards the east, with Nodes B and C being triangular in plan, while D is squarer, and the last, northernmost section runs in a straight line from the third section. The last Node is triangular in the opposite direction to the others, as part of the original concept that further sections would have bent back towards the hill, creating an S shape. The Nodes contain lifts, stairs and toilets, and all Nodes except A have striking open spiral stairs. The vertical structure consists of the Nodes, and evenly spaced supports formed as fin-like walls, which are expressed as tall piers on the rear, breaking up the space under the overhanging floors in a rhythm of thicker and thinner walls, while on the front the floors are partly cantilevered, thrusting forward on the first three floors to support only the spandrel beams, then as vertical walls for the next three floors, then as spandrel supports again for the final two floors. All concrete surfaces are in off-form concrete, with the spandrels, some columns and the underside of the floors smooth finished, while all other surfaces are vertically ribbed and bush hammered. This finish was achieved by placing vertical timber rods in the formwork, resulting in smooth semi-circular grooves 50mm deep and protruding nibs, which were then hammered every 100mm vertically, resulting in a "random but consistent pattern [that] is a remarkably successful marriage of an ancient building material and patient handiwork". It was the largest example of the technique in Australia at the time. References Buildings of the Australian government Office buildings in Canberra Brutalist architecture in Australia