" Factory, etc. not to be established without permission of Commissioner. 1) No person shall, without the previous permission in writing of the Commissioner, establish in any premises, or materially alter, enlarge or extend , any factory, workshop or trade premises, in which it is intended to employ steam, electricity, water or other mechanical power. 2) The Commissioner may refuse to give such permission, if he is of the opinion that the establishment, alteration, enlargement or extension of such factory, workshop or trade premises, in the proposed position would be objectionable by reason of the density of the population in the neighborhood thereof, or would be a nuisance to the inhabitants of the neighborhood"