23H Page 92
Even in cases where the slides are only moderately strong, it is often worth while, at the end of setting, to "run back to confirm" a setting which has possible competitors.
(f) Random setting of perfect wheels.
When some wheels are perfect or nearly perfect it should be possible to set messages by taking each such wheel at two (odd and even) random settings, and using these to set the other wheels. Perhaps the simplest method is to allow the perfect wheels to step while the other wheels are run round a few times. In this way it is feasible to do what are in effect 3- or 4- wheel break-ins. [R1 pp. 19, 22-25, 29; R2 pp. 19, 21; R4 pp. 24, 28.]
23H FLOGGING RUNS
(a) Flogging.
Flogging is trying all methods which may possibly help to set a message. This may be done
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(i) because of intelligences or cryptographic priority.
(ii) because of lack of work. (iii) for ostentatious display (towards D.O. or Wrens). |
(b) Flogging Break-ins.
The usual runs are 1+2. and 3+4x. If these fail on a message which is to be flogged, 2+5, 4+5, 1+3, 2+4 are all reasonable; but see R4 p. 15.
Note: Except with Χ2 limitation the only 2-wheel break-ins are i + j = . or x .
If there is any doubt about Χ2 limitation, break-ins can be done on both assumptions.
Break-ins with spanning can be used on a generous scale. [of 23F(f)].
(c) 3- and 4- wheel runs.
A more powerful method is to do a break-in on more than two wheels. It might be possible to do a complete 3- wheel run in 10 hours or so, but ΔD characteristics happen to be such that no 3-wheel run is very advantageous. 4-wheel runs, in particular 1=2=4=5/ are [illegible], but run completely they are intolerably long [but see: 918]
A compromise is to do a 1+2 break-in followed by 4=5=/1=2 at all Χ1Χ2 settings which score more than 2σ, naturally taking the higher scores first. This has sometimes succeeded, but it is long and laborious.
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