Note 58 — Chapter XIV · CAUSES OF CHANGE
Reading edition
Sometimes appearances may be deceptive: when [nr, mr] become [ndr, mbr], it looks on the paper as if something had been added and as if the transition therefore militated against the principle of ease: in reality, the old and the new combinations require exactly the same amount of muscular activity, and the change simply consists in want of precision in the movement of the velum palati, which comes a fraction of a second too soon. If anything, the new group is a trifle easier than the old. See LPh 5. 6 for explanation and examples (E. thunder from þunor sb., þunrian vb.; timber, cf. Goth. timrian, G. zimmer, etc.).