Projection introduced by Karl Siemon in 1935, it was published and forgotten – then independently recreated by Waldo R. Tobler in 1966, who named it. Implemented in d3-geo-projection by @JasonDavies.
With the loximuthal projection, rhumb lines (aka loxodromes, in green) are straight lines. Formula adapted from http://www.mathpages.com/home/kmath502/kmath502.htm
Mouse over the map to change the reference parallel.