A cosmetic composition comprises a) an N-acyl amino acid compound selected from the group consisting of N-acyl amino acid, its isomers, its salts, derivatives thereof, and mixtures thereof, and b) hexyldecanol. A geared motor disposed below a cylinder. Additionally, the method further comprises a feedback control responsive to an exhaust gas oxygen sensor to adjust said fuel delivered from said multiple fuel tanks to the engine to maintain engine air-fuel ratio around stoichiometry. A large part of an inner propagation light is inner-reflected twice by the slopes successively and direction-converted as to be directed to the emission face.