The sea-level muon momentum spectrum in t,he range 0'7-30 GeV/c has been measured at Nottingham, England, at zenith angles of 0�,30� W., and 45 oW., based on 1052, 1010, and 1033 particles respectively. Agreement is found at 0� with the results of Owen and Wilson (1955) and disagreement with those of Caro, Parry, and Rathgeber (1951). The same form of disagreement occurs with the results of Moroney and Parry (1954) at 30� obtained using the same instrument as Caro, Parry, and Rathgeber. Within the statistical accuracy of the experi~ent satisfactory agreement is found with the theories based on either single level or extended production of the muons.