(я посмотрел вокруг = огляделся торжествующе и сказал себе) – “Here at least, then, my labor has not been in vain (здесь, по крайней мере, значит, мои труды не были напрасны; then – тогда; значит; в таком случае; итак).”
When I had finished, I felt satisfied that all was right. The wall did not present the slightest appearance of having been disturbed. The rubbish on the floor was picked up with the minutest care. I looked around triumphantly, and said to myself – “Here at least, then, my labor has not been in vain.”
My next step was to look for the beast which had been the cause of so much wretchedness (мой следующий шаг был – искать то животное, которое было причиной стольких несчастий; to look for – искать: «смотреть за»; so much – так много; wretched – бедный, несчастный); for I had, at length, firmly resolved to put it to death (ибо я наконец твердо решился предать его смерти; to put to death – предать смерти; to put – класть, ставить). Had I been able to meet with it, at the moment (будь я способен = если бы я смог встретиться с ним в тот момент), there could have been no doubt of its fate (не могло бы быть никакого сомнения в его судьбе); but it appeared that the crafty animal had been alarmed at the violence of my previous anger (но показалось = но, видимо, коварный зверь был испуган жестокостью моего предыдущего гнева; to alarm – встревожить), and forbore to present itself in my present mood (и не спешил показываться: «представлять себя» при моем нынешнем настроении; to forbear – воздерживаться, терпеть; to present – представлять).

My next step was to look for the beast which had been the cause of so much wretchedness; for I had, at length, firmly resolved to put it to death. Had I been able to meet with it, at the moment, there could have been no doubt of its fate; but it appeared that the crafty animal had been alarmed at the violence of my previous anger, and forbore to present itself in my present mood.
It is impossible to describe, or to imagine, the deep, the blissful sense of relief (невозможно описать или вообразить глубокое, блаженное чувство облегчения; bliss – блаженство) which the absence of the detested creature occasioned in my bosom (которое отсутствие ненавистной твари вызвало в моей груди)