moment he passed the Trade Test, he is put into a skilled category and therefore, eligible to be considered for such promotional post. For the purpose of the record it is apposite to mention that in the meantime, the petitioner has been appointed to the post of Mate(Electrical) with effect from 7th January, 2010. Still the petitioner persued his earlier claim that to be posted at the promotional post of Junior Engineer (Electrical & Mechanical). The rules concerning the consideration for such promotional post is categorical and a specific which is not denied by either of the parties. The eligibility criteria for the promotional post of Junior Engineer (Electrical & Mechanical) is restricted to a Highly Skilled Tradesman with 8 years service and a Skilled Tradesman with 16 years of service. It appears that after acquiring the qualification i.e. Diploma in the Mechanical Engineering from a recognized Institute, the petitioner is still at the Semi- skilled category and does not acquire a category of Highly Skilled Tradesman or Skilled Tradesman. The authorities being the creature of statute cannot travel beyond the ambit of the Recruitment Rules applicable in this regard. The petitioner has not challenged the Recruitment Rules i.e. ultravires to the Constitution or the Statutory Act. If the rules provide the modalities and mechanism for recruitment to a promotional post, authorities cannot travel beyond the peripheral thereof and have to act