What does the author suggest by the word 'placid'?

Directions: Read the passage and answer the question that follows.

While I stood drinking in the beauty of this placid scene, I became conscious of an alteration. In a moment, a sole porter emerged from his midday nap, operated a signal that clanked noisily into position, and then ambled slowly towards me for my return-half-ticket, whilst I remarked that his red amiable face and easygoing gait were in perfect harmony with the tranquil surroundings. A wisp of smoke on the horizon with a dark snake crawling beneath it announced the approach of the train. As it drew nearer, the deep silence of the place was gradually displaced by a creaking of brakes and a hissing of steam. Save for myself, no one entered the train and no one alighted. The porter with leisurely expertness, trundled a couple of milk churns on board, the door was slammed, the guard signalled to the driver, and we moved off, leaving the small station once more to its drowsy silence.