英文の和訳をお願いします。
できるだけ、意訳はなしで訳していただけると助かります。
スペルミスには注意しましたが、何か間違い等があったらすみません。
お願いいたします。
It was an Italian naturalist called Spallanzani, in the eighteenth century, who first started to investigate the flight of bats, and by the unnecessarily cruel method of blinding several bats he found that they could still fly about unhampered, avoiding obstacles as though they were uninjured. But how they managed to do this he could not guess.
It was not until fairly recently that this problem was solved, at least partially. The discovery of radar, the sending out of sound－waves and judging the obstacle ahead by the returning echo, made some investigators wonder if this was not the system employed by bats. A series of experiments was conducted, and some fascinating things were discovered. First of all, some bats were blindfolded with tiny pieces of wax over their eyes, and as usual they had no difficulty in flying to and fro without hitting anything. Then it was found that if they were blindfolded and their ears were covered they were no longer able to avoid collisions and, in fact, did not seem at all keen on flying in the first place. If only once ear was covered they could fly with only moderate success and would frequently hit objects. This showed that bats could get information about the obstacles ahead by means of sound－waves reflected from them. Then the investigators covered the noses and mouths of their bats, but left the ears uncovered, and again the bats were unable to fly without collision. This proved that the nose, ears and mouth all played some part in the bat´s radar system. Eventually, by the use of extremely delicate instruments, the facts were discovered. As the bat flies along, it emits a continuous succession of supersonic squeaks, far too high for the human ear to pick up. They give out, in fact, about thirty squeaks a second. The echoes from these squeaks, bouncing off the obstacles ahead, return to the bat´s ears and, in some species, to the curious fleshy ridges round the creature´s nose, and the bat can thus tell what lies ahead and how far away it is. It is, in fact, in every detail the principle of radar.
以上です。
お礼
これで、問題点は明確になりました。 (1)特に、keep watch on judgments and cruel deeds について、「争いや暴力沙汰を監視する」 という解釈が辞書から導いたことに驚きました。 (2)ハイフォンの解釈について 直前の言葉の説明、話題の転換に使われる（とのこと）。 （＊これから述べることは）などとしたのは、 質問者の勝手な解釈でした。 こうした苦し紛れの勝手な解釈をしてはならないだけに、 意味がよくわかりました。 ありがとうございました。