The profession of Jack the Ripper.

[John G]

If we had many more killings we may be able to draw some conclusion based on moon phases, but with a mere handful random selection give about a 20% chance if him killing on a full moon.

Yes, a very good point. The apparent connection with moon phases may be simply coincidental.

[John G]

[QUOTE=Pierre;372607]

But with inadequate street lighting conditions would have been far worse than would be the case today.

No mutilations were done there. In what places could the question of light be relevant? Probably not in Buckīs Row. And definitely not in Millerīs Court. So it might be a relevant question just for Hanbury Street and Mitre Square.



The key word must be skill.

If the external conditions were no good, the internal conditions must have been sufficient. That is, his own knowledge or skill must have been enough. So how skilled was he? How much skill did he need? On what level did it have to be?

Perhaps he was ambidextrous. Perhaps he was very smart. Perhaps he knew what he was doing.

Like this one:

http://www.youtube.com/watch?v=8HPF9uPllt8

Regards, Pierre

The point is this: It is questionable as to whether he had any skill at all, for instance, even a butcher would know that you don't need to remove the intestines in order to access the uterus. Therefore, Dr Bond may well have been correct.

[Hercule Poirot]

Perhaps people back then were simply better conditioned to see and operate in the darkness?

I don't think our 'ancestors' back then had better night vision than now. This may help in understanding how human night vision works:

Rhodopsin is the key to night vision. it is the chemical that the rods use to absorb photons and perceive light. When a molecule of rhodopsin absorbs a photon, it splits into a retinal and an opsin molecule. These molecules later recombine naturally back into rhodopsin at a fixed rate, and recombinati*on is fairly slow.

So, when you expose your eyes to bright light, all of the rhodopsin breaks down into retinal and opsin. If you then turn out the lights and try to see in the dark, you can't. The cones need a lot of light, so they are useless, and there is no rhodopsin now so the rods are useless, too. Over the course of several minutes, however, the retinal and opsin recombine back into rhodopsin, and you can see again.

A fun fact: The retinal used in the eye is derived from vitamin A. If a person's diet is low in vitamin A, there is not enough retinal in the rods and therefore not enough rhodopsin. People who lack vitamin A often suffer from night blindness -- they cannot see in the dark.

Cheers,
Hercule Poirot.

[GUT]

Well, as full moons only occur about once a month I doubt this was anything more than coincidental-unless he happened to be either an astronomer or a werewolf, of course!

If we had many more killings we may be able to draw some conclusion based on moon phases, but with a mere handful random selection give about a 20% chance if him killing on a full moon.

[GUT]

Perhaps people back then were simply better conditioned to see and operate in the darkness?

This could be a big factor.

[Pierre]

[QUOTE=John G;372586]But with inadequate street lighting conditions would have been far worse than would be the case today.

In fact, it was so dark in Dutfield's Yard that Joseph Lave couldn't even see the door to get back into the club.

No mutilations were done there. In what places could the question of light be relevant? Probably not in Buckīs Row. And definitely not in Millerīs Court. So it might be a relevant question just for Hanbury Street and Mitre Square.

And, of course, the question isn't whether the eviscerations were possible at all, but whether, in the case of Chapman and Eddowes, they could have been carried out with the level of skill suggested by the medical professionals

The key word must be skill.

If the external conditions were no good, the internal conditions must have been sufficient. That is, his own knowledge or skill must have been enough. So how skilled was he? How much skill did he need? On what level did it have to be?

Perhaps he was ambidextrous. Perhaps he was very smart. Perhaps he knew what he was doing.

Like this one:

http://www.youtube.com/watch?v=8HPF9uPllt8

Regards, Pierre

[SirJohnFalstaff]

Sorry, Pierre, you've lost me there, he killed at night/early morning, but he must have been able to see something so how is this avoiding light?
Cheers
Albert

It's quite possible that Chapman was killed after sunrise.

[John G]

Perhaps people back then were simply better conditioned to see and operate in the darkness?

But with inadequate street lighting conditions would have been far worse than would be the case today. In fact, it was so dark in Dutfield's Yard that Joseph Lave couldn't even see the door to get back into the club.

And, of course, the question isn't whether the eviscerations were possible at all, but whether, in the case of Chapman and Eddowes, they could have been carried out with the level of skill suggested by the medical professionals.

[Damaso Marte]

Perhaps people back then were simply better conditioned to see and operate in the darkness?

[Albert]

Hi Pierre, thanks. I take your point but this doesn't help to explain how Jack was able to see well enough to carry out the extractions. John G has pointed out that a bulls-eye lantern would not have provided enough light for this work.
Regards
Albert

[Pierre]

Well, as full moons only occur about once a month I doubt this was anything more than coincidental-unless he happened to be either an astronomer or a werewolf, of course!

I donīt think it was a coincidence. He never killed in a week where there was a full moon. Never on a night when there was even an actual half moon (with at least 50 % illumination).

He always chose the new moon or the last quarter.

The most illuminated night was the night of the murder on Polly Nichols. That murder was also done right in the street.

I am merely stating the obvious.

Regards, Pierre

[John G]

Look at the lunar phases. As you can see, he avoided the full moon.

Regards, Pierre

Well, as full moons only occur about once a month I doubt this was anything more than coincidental-unless he happened to be either an astronomer or a werewolf, of course!

[Pierre]

Sorry, Pierre, you've lost me there, he killed at night/early morning, but he must have been able to see something so how is this avoiding light?
Cheers
Albert

Look at the lunar phases. As you can see, he avoided the full moon.

Regards, Pierre

[Albert]

Sorry, Pierre, you've lost me there, he killed at night/early morning, but he must have been able to see something so how is this avoiding light?
Cheers
Albert

[Pierre]

http://www.casebook.org/victorian_london/weather.html[/URL]

Hi Albert,

I believe Particia Cornwell did some research and the results were quite poor. I've also found a You Tube clip posted by Monty!
https://m.youtube.com/watch?v=_mOEPlbbAvo

However, to my mind, even if the light quality was equivalent to, say, that of a modern torch you would still have less light available than from a modern operating theatre or on a bright summer's day. So the essential problem remains: how could a perpetrator remove organs, demonstrating an exceptional level of skill, in far from ideal lighting conditions, whilst using a Victorian knife and applying Victorian surgical techniques?

If the light wasnīt bright, maybe he was?

He obviously avoided light:

http://www.casebook.org/victorian_london/weather.html

Regards, Pierre