Fashionable modern houses of the thirties in the Streamline Moderne style were sometimes described as being like ocean liners, with walls, windows and balconies all sweeping around corners. By the 1940s these details were entrenched into suburban designs. The 'Waterfall' or 'Waterfall Front' style came to be known as such from the use of descending curves in chimneys, fence pillars and other vertical elements. Robin Boyd, the Australian architect and writer, noted that three was 'the key to decorative smartness'; three steps usually being used for the waterfall effect and featured parallel lines were often in threes.