This observation showed that in a rather beautiful way the rotor positions left their fingerprints upon the cipher-text, when the traffic was considered as a whole.
这项观察表明，如果把整个通信系统看作一个整体的话，盘位会在密文中留下很漂亮的蛛丝马迹。
In fact they left just three fingerprints, the cycle-lengths of each of the three letter-connection tables.
事实上，它们会留下三条线索，也就是这三张字母关系表的轮换长度。
It followed that if they possessed a complete file of the cycle-length fingerprints, three for each rotor position, then to determine which rotor position was being used for the first six letters all they would have to do was to search through the file.
接下来，如果他们拥有一份完整的轮换长度档案，记录每一种盘位的轮换长度，那么只需要查找这份档案，就可以确定当前使用的盘位。
The snag was that there were 6 × 17576 possible rotor positions to catalogue.
问题是，这需要登记6×17576种可能的盘位。
But they did it.
然而他们竟然做到了。
To help in the work, the Polish mathematicians devised a small electrical machine which incorporated Enigma rotors, and which automatically produced the required sets of numbers.
在实践中，波兰数学家们制造了一台包含谜机转盘的小型电动机器，可以自动地统计需要的数据。
It took them a year to do the work, the results of which were entered on file cards.
他们花了一年的时间，制成了一套档案卡，
But then the detective work was effectively mechanised.
后面的查找工作就有效地机械化了。
It only took twenty minutes to look through the file to identify the combination of cycle-lengths which matched the cipher traffic of the day.
只需要20分钟，就可以在这些档案卡中，找出与密文的轮换长度相匹配的盘位。
This would reveal the positions of the rotors as they stood during the encipherment of the six indicator letters, and from that information, the rest could be worked out and the day's traffic read.
这将揭露编码开头六个字母所使用的盘位，由此可以解出其余部分的盘位，然后这一天的信息也就全都破解了。