Novel compounds acetoxymethylacenaphthylene and hydroxymethylacenaphthyleneare disclosed. First, a repeating unit time interval is designated for conducting the plurality of sessions. The engaging process of the hydraulic clutch includes a first engaging sub-process for rapidly raising the oil pressure to the hydraulic clutch for a predetermined period and a second engaging sub-process for gradually raising the oil pressure to the hydraulic clutch which has been temporarily dropped subsequent to the first sub-process. so as to selectively set the molds 10 and 11 to the intermediate clamped state and the final clamped state. The cutter block is arranged and designed to move at least the first axial distance with respect to the body to contact the sleeve in response to hydraulic pressure in the bore. An electronic engine control provides the variable demand signal to the metering assembly.