It was the natural way to depict it since the line doesn't form a true circle. Roberts sells posters of his various map designs at tubemapcentral.com. For more stunning Tube-related design ...

the Circle line name was used for the first time. But until 1949 it was not given a distinct identity on the Tube map, finally adopting its distinctive yellow colour in that year. For the next 60 ...

the Circle line name was used for the first time. But until 1949 it was not given a distinct identity on the Tube map, finally adopting its distinctive yellow colour in that year. For the next 60 ...