Let $U_1,\dots,U_n$ be iid random variables uniformly distributed on the interval $[0,1]$, with the corresponding order statistics $U_{(1)}\le\dots\le U_{(n)}$. Let $G_i:=U_{(i+1)}-U_{(i)}$ for $i=0,\dots,n$, where $U_{(0)}:=0$ and $U_{(n+1)}:=1$.

It is now a textbook fact that the joint distribution of $G_0,\dots,G_n$ is the same as that of $R_1,\dots,R_{n+1}$, where $R_i:=H_i/(H_1+\dots+H_{n+1})$ and the $H_i$'s are iid standard exponential random variables.

Moran, page 93 ascribes mentioning of this fact to Fisher, and a proof of it -- without a specific reference -- to Clifford.

Thus, here is my question:

Can one give a reference to that paper by Clifford, assuming it does exist?