The Hill eucyclic projection is available as d3.geo.hill in the geo.projection D3 plugin. With a ratio of 0 rather than the default 1, this projection becomes the Maurer No. 73. The Hill projection is psuedoconic and equal-area. As the ratio approaches ∞, the projection converges to the Eckert IV.
Changed /mbostock/raw/4090846/world-50m.json to a local referenece