Original Hubble diagram units incorrect? Figure 1 from Hubble 1929 (original paper with open access pdf) has velocity with units of km. Is this just a typo or was there a reason the plot is printed this way?
It is in fact supposed to be in $\mathrm{\frac{km}{s}}$ (KILOMETRES per second).

I think that whoever authored the paper, probably took it as a random shortcut and assumed anyone reading it would either have read the paper and understand it is supposed to be $\mathrm{\frac{km}{s}}$, or just assume it from the fact it says velocity.