The Margin For Error.

[Wickerman]

I just want to endorse both Steve and Wickerman's posts. Stated times are generally estimates because most people, if they looked at a clock at all, did so some time prior to the event they are giving a time for (so they had to estimate what time it was at event X having looked at a clock previously).

Thankyou Jeff.

There are some incidents that cannot be dealt with as a sequence, for example the interaction in Mitre Square we've just been going over again on another thread.
After Lawende left, everything that might have happened can only be determined by stated times, either by watches, clocks or estimates.
The main contributors Watkins & Harvey never saw each other and neither saw anyone else on their rounds so we can't apply a sequence of events.

[Herlock Sholmes]

Hopefully we wouldn’t waste time debating whether the Whitechapel murders were a series of suicides or not, but it’s equally remarkable how much time has been wasted due to the fact that it still won’t be accept by some what really shouldn’t require discussion….that a margin for error should automatically be considered when discussing all stated times or estimated periods of time. It’s about as basic as it gets. We’ve had George producing a quote from an expert in Victorian timekeeping who said that he thinks that we would have been lucky to find a clock less that 10 minutes out. We’ve had Jeff producing a quote that talks about the inaccuracy and poor synchronisation of clocks in London in 1908 that was causing real problems. We have had a very good first post from Hyperfocal who, unlike the rest of us, clearly has a knowledge of clocks and watches, and he warns us of the potential inaccuracy of Victorian clocks and watches. But the most relevant point for me is our own experience of modern day clocks and watches. How these are often wrong; how often these are poorly synchronised. And how often we estimate periods of time inaccurately.

The accusation is often made that times are being ‘moved’ to suit a particular point of view but this clearly isn’t a sustainable argument as it’s always stressed that a margin for error has to involve a plus or a minus figure and that just because we allow for a margin it doesn’t mean that we should assume clock error or poor synchronisation….only that we should consider and accept the possibility, so that suggestions, possibilities or theories shouldn’t be dismissed on the grounds of stated times or of estimated periods of time being accurate.

How much margin for error should be allowed for is a question that has no answer. It’s down to individual judgment and interpretation. What is certain though is that no assessment of any aspect of the case can be considered valid without an acceptance that a margin for error has to be applied. It really is as basic as that.

[Elamarna]

Thankyou Jeff.

There are some incidents that cannot be dealt with as a sequence, for example the interaction in Mitre Square we've just been going over again on another thread.
After Lawende left, everything that might have happened can only be determined by stated times, either by watches, clocks or estimates.
The main contributors Watkins & Harvey never saw each other and neither saw anyone else on their rounds so we can't apply a sequence of events.

I think we can postulate that Harvey approached the square between the two beats of Watkins( assuming we do not speculate Watkins did not miss a beat, having a cup of tea.).

[PRIVATE INVESTIGATOR 1]

I have no doubt it was half-past one o'clock when we rose to leave the club ... by seeing the club clock and my own watch.

(Joseph Lawende)

[Herlock Sholmes]

The three questions would then be, a) how accurate was the club clock? Then b) had Lawende set his watch by that clock? And c) how quickly did they leave after they’d sat until 1.30 (did they leave at exactly 1.30 by the clock or could it have been 2 or 3 minutes later after putting coats on, saying good nights etc)?

[PRIVATE INVESTIGATOR 1]

Lawende did imply that he had not used the club clock to set his watch's time.

[JeffHamm]

Thankyou Jeff.

There are some incidents that cannot be dealt with as a sequence, for example the interaction in Mitre Square we've just been going over again on another thread.
After Lawende left, everything that might have happened can only be determined by stated times, either by watches, clocks or estimates.
The main contributors Watkins & Harvey never saw each other and neither saw anyone else on their rounds so we can't apply a sequence of events.

Hi Wickerman,

I may be missing the main issue that you're referring to above, in which case my apologies. I do see a fair bit that we can use to form sequences though.

We know that PC Harvey's previous patrol he does not see a couple at Church Passage (otherwise we would expect some record of this; while absence of evidence applies, it's a reasonable starting point given the police were on the lookout for couples). We know Lawende and co see the Church Passage Couple, and then leave, so the CPC had to arrive after PC Harvey's previous patrol of the area, and before Lawende and co emerge. We know that by the time PC Harvey patrols Church Passage just before the murder is discovered, he does not see the CPC, so between Lawende and co moving on and PC Harvey's patrol of Church Passage, the CPC has left again.

Also, we know that PC Harvey doesn't hear the whistle until he's on the last leg of his beat, so we know his patrol of Church Passage occurs prior to Morrison's whistle blowing, and we know that occurs after PC Watkin's finds the body, so PC Harvey patrols Church Passage prior to the discovery. It is the whistle blowing that can be used to try and align PC Watkins and PC Harvey's sequences, as that is the common event that ends up connecting them.

Finally, Lawende and co also point out they hang out by the club until the rain stops, or at least eases up enough for them to move on. So we know that the Lawende and co, and the CPC, did not move from their locations until after the rain (I'm presuming it was a sudden downpour if it was enough to keep them from moving on, and generally such bursts don't last a long time in my experience, but UK weather is a beast unto itself, so I could be wrong on that).

There might be crime scene evidence that indicates whether or not Eddowes was killed and mutilated before or after that downpour. If she's killed before the rain, then she's not part of the CPC, if she's killed after the rain, then the CPC remains viable as a true sighting. Even if the CPC still isn't Eddowes and JtR, and they entered from another direction, if she was killed after the rain stopped, then we can still use Lawende and co's "time" as an indication of when Eddowes and JtR get to the crime scene (or at least, when the murder occurs). Basically, if the murder was post-rain, then we cannot create "more time for the murder" by saying Eddowes and JtR entered the area while the CPC were chatting, and the murder started well before Lawende and co moved on. That sort of thing. I just can't recall if it is established for sure that the murder was definately after the rain stopped?

Anyway, we also know that Morrison at some point, shortly before PC Watkin's arrival, opens the door to the warehouse during his cleaning (I think to sweep out dirt or something). So PC Harvey Patrols Church Passage, Morrison opens the warehouse door, PC Watkins arrives is one sequence, the other might be Morrison opens the door, PC Harvey patrols Church Passage, PC Watkins arrives would be the other ordering.

When building in other information, like mapping out PC Harvey's beat, and estimating his average patrol speed, and statements from Morrison about when he opened the door relative to PC Watkin's calling on him for assistance, the "door opening" and PC Harvey's patrol end up very close together, so either of those sequences are possible - making either of those events a possible reason for JtR to exit the scene (if he's still there of course).

Amidst all of the above sequences, we have to fit into the puzzle the sequence "Eddowes ends up at the crime scene; JtR is also at the crime scene at the same time as Eddowes; Eddowes is attacked, murdered, mutilated; JtR leaves the area" The easiest sequences would be one where Eddowes and JtR enter Mitre Square and go to the crime location together, but I've phrased it as above to avoid that being seen as a necessary condition.

The above "crime sequence" thread has to find a place in our "evidential sequence" where it fits in. While in many ways it seems to connect with aspects of the CPC sequence, in the simulations I've done, one can fit in the crime sequence by having Eddowes and JtR enter from any of the other possible entrances as well. We just have less information about those alternative routes, which makes the CPC appear to be the only real solution. (It's like the old joke about searching under the street light for your wallet that you dropped in the dark alley because the light is better).

One of the simulations I put together for Mitre Square explored multiple entrance and exit routes for the crime sequence, and in the end, I think almost any of the possibilities can work, although some seem rather improbable (I can't see JtR sticking around through PC Harvey's patrol of Church Passage, then waiting long enough to be able to exit out through Church Passage as well - it can work, but it seems improbable. I suppose one argument could be that PC Harvey patrols Church Passage, alerts JtR who is about to flee when Morrison then opens the door, causing JtR to freeze trying to work out how to get out of there, PC Harvey turns around, Morrison finishes his sweeping and the door closes, and JtR exits via Church Passage because he now knows no police will come down there, and he saw PC Harvey turned right so he can exit and turn left). No, I'm not pushing that, just throwing out how one has to consider all avenues. I would rate that one low on the probability scale given what we have to work with.

- Jeff

[Herlock Sholmes]

Lawende did imply that he had not used the club clock to set his watch's time.

Where did he imply that?

[PRIVATE INVESTIGATOR 1]

Where did he imply that?

Well, there would hardly have been any point in his referring to two clocks if one had been set to agree with the other.

[Herlock Sholmes]

Well, there would hardly have been any point in his referring to two clocks if one had been set to agree with the other.

But we can’t assume that. He just mentioned seeing both the club clock and his watch so he was stressing that he couldn’t have been mistaken about the time.

[PRIVATE INVESTIGATOR 1]

But we can’t assume that. He just mentioned seeing both the club clock and his watch so he was stressing that he couldn’t have been mistaken about the time.

... because he used two clocks, which he knew to have been set independently.

[Herlock Sholmes]

... because he used two clocks, which he knew to have been set independently.

That’s simply an assumption. Why assume that an unknown is known?

[PRIVATE INVESTIGATOR 1]

It is not simply an assumption.

We have no reason to think that Lawende set his watch to agree with the club clock's time.

[Herlock Sholmes]

It is not simply an assumption.

We have no reason to think that Lawende set his watch to agree with the club clock's time.

And we have no reason to think that he didn’t. He might not have done but we shouldn’t assume that he hadn’t simply because he mentioned his watch and the clock. For example - we don’t know the location of the club clock in relation to where Lawende was sitting, so it might have been the case that he checked his watch, then they stood up to leave and as they headed for the door they passed the clock, or that the clock was then directly ahead of them and so in view. So Lawende could then stress that he couldn’t have been mistaken because he looked at his watch and then saw the clock. One confirming the other. It wouldn’t have mattered if he’d originally set his watch by the clock.

This isn’t a particularly important or significant point but I think that we should be wary of assuming that our deductions are correct when we don’t know the full circumstance's

[Curious Cat]

Is it PC Watkins or PC Harvey that goes by the time on the Post Office clock?

Does that correlate in any way with the time on the Imperial Club's clock and Lawende's watch? Where are they on their beats at those times and do they run in synch at those points?