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breaking as well as setting.
For the history of setting in the Colossus period the reader is referred to the references in the earlier part of the chapter and to the index of the Research logs.
In conclusion we give a list of some difficulties that occurred in the early days, particularly in the Heath Robinson period:-
| (1) | Sprockets tearing and stretching. |
| (2) | Tapes breaking and coming unstuck. |
| (3) | Failure of experiments with oiled tape. |
| (4) | Incorrect setting up of wheel settings and wheel patterns on Tunny. |
| (5) | Blurred figures on Robinson printer and running out of printing ink. |
| (6) | Putting tape on Robinson back to front. |
| (7) | Inaccurate punching of start and stop signals - high standard required by Health Robinson. |
| (8) | Incorrect setting of repeat dials. |
| (9) | Difficulty in calculation of wheel settings from readings, especially motor settings. |
| (10) | Incorrect setting of Χ2 when contracting a tape on Tunny. |
| (11) | Mysteriously long time taken for production of de-chi tapes and contractions. |
| (12) | Prevalence of transient faults on machines which were therefore difficult to diagnose. |
| (13) | Badly written figures and figures incorrectly written down. |
| (14) | Runs not checking with de-chi tape and other mysteries. |
| (15) | Insufficient handing over from one shift to the next. |
| (16) | Print-outs with letters erroneously inserted or omitted by the machine. |
| (17) | Habit of guessing the average from readings in the run, instead of calculating it in advance. |
| (18) | Using even length of tape for runs unvolving Χ4. |
| (19) | Inaccurate counting by Heath Robinson. |
| (20) | Damaging tapes by maltreatment. |
| (21) | Numerous slides in tapes provided at that time by Knockholt. |
| (22) | Presumed certainty of 4σ on a long run. |
| (23) | Running out of benzene, squared paper, and method of obtaining benzene, paint brushes and rubbers from local sources. |
| (24) | Difficulty of getting supplied with the small machines like hand counters and stickers. |
| (25) | Setting tape in wrong place (on any machine). Forgetting Χ2 lim. for Tunny contraction. Forgetting to reset a tape when restarting a job. |
| (26) | Sickness due to intolerable working conditions. |
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