Sentence:  Art. 33. All Plying boats, with the exception of two which are to be weekly appoin[t]ed by the Chief Commissary of Police and Harbour Master, and at <WSD>gunfire</WSD> in the evening to be placed in a tier alongside of the Quay or at a place to be pointed out by these Officers and fastened by a claim and a padlock, the key of which is to be kept by the Porter on duty or by the Police Guard who is to release them at <WSD>gunfire</WSD> in the morning. 
Meaning of the word marked with <WSD> tags:  The time of firing of the morning gun or the evening gun.