Whoever hires or engages or employs, or promotes, or connives at the hiring, engagement or employment of any person to join or become a member of any unlawful assembly, shall be punishable as a member of such unlawful assembly, and for any offence which may be committed by any such person as a member of such unlawful assembly in pursuance of such hiring, engagement or employment, in the same manner as if he had been a member of such unlawful assembly, or himself had committed such offence.