why do you suppose...

[Stacy Clifford]

Keep in mind that in Europe they made some thrusting blades that didn't even really have edges at all (and could barely even be called a blade). There were some rondels that had the cross section of an equilateral triangle, and in the Armeria Real in Madrid I saw an estoc with a square cross section that was basically a four-foot railroad spike with a sword hilt! They may not have been the norm, but I get the impression that they weren't all that uncommon either. Against especially dense weaves of mail or tempered links you may have had just as much chance of damaging the edges of your dagger as puncturing the mail, so they dispensed with edges altogether in favor of pure structural reinforcement for thrusting. You don't have to worry much about damaging a big icepick, and you can bet it will do plenty of damage. That estoc in Madrid might even puncture plate like a bec de corbin. I think edges are more useful against softer materials, but against harder stuff it just comes down to pure force.

[Maxime Chouinard]

Well, your knowledge about history is much wider than mine, but if what you say is true, then how can you explain samurai in the edo period going away from such a good piercing armory tanto to another tanto not so good at stabbing and piercing... why would they do so... mmm... tradition? Perhaps having a tanto that looks better for killing yourself (seppuku) is more honorable? that would be pretty traditional choice too, right?

They still made armor piercing daggers, actually a lot; the ones I showed you are from the Edo period. But there wasn't much need for it, so having a knife that can cut and pierce very well on unarmoured foes (and cost less, since less material is used...) and do other everyday works was a much better choice. Some even preferred to carry a wakisashi in place of the tanto. As much as books like hagakure would like us to believe, seppuku was a very rare occurance, and no one except some really morbid and nevrosed people would have wore something that was only intended for killing themselves.

Well, you just gave an example in which two edges are an advantage but there are many more; against a a mail for instance. Just for the sake of a mental experiment imaging a unique steel ring from the mail, and imagine you try to thrust through it.

I think Stacy answered this one (I agree with you completely Stacy). Two edges is good against soft targets, like a jack as it shears through, but not necessarily against maille because there is nothing to cut. In that case you need enough power and a tip that can enter a ring to burst it open.

I don't really know if you're comparing the best Japanese possible steel with the best European possible steel. I guess that most swords in Europe and Japan were mass produced for soldiers, and the quality of those blades could not be the best... are the mass produced steels the ones you're comparing?

It's a fact that rockwell hardness is in general, higher on japanese blades. Now it doesn't make anything better, nor does it mean that there weren't any exceptions (blade hardness was very variable in europe, I'm pretty sure it would have been in Japan too). All I said was that the different characteristic of each swords would tend to make them much more alike in their capacity than we would think. Michael Edelson test revealed that the katana he used did nearly as good as the longswords on a jack, despite not being handled in a half-sword fashion like the others, and not having a tip that is best for thrusting (as an o-kissaki for example). As for the rest I think I made my point (no pun intended).

[Francisco Urbano García]

Well first of all I want to thank you Maxime, and Stacy too, cause I am learning a lot in this debate.

Keep in mind that in Europe they made some thrusting blades that didn't even really have edges at all (and could barely even be called a blade)...

Well, actually I don't, that's the point. I was arguing that a blade with two edges is better at thrusting that a blade with just one.

If we talk about the best piercing tool blade or not, then I believe no blade is better than this for piercing:

http://home.att.net/~licata_knives/warhammer.jpg

Just designed to place all the energy of the blow in one strong sharp point. If instead a cylinder shape point you had a blade (flat) point it could not take too much energy and it might break.

But again, for blades and thrusting... straight and two edges.

They still made armor piercing daggers, actually a lot; the ones I showed you are from the Edo period. But there wasn't much need for it, so having a knife that can cut and pierce very well on unarmoured foes (and cost less, since less material is used...) and do other everyday works was a much better choice.

Well, just a reminder, the whole thing about the tanto is about me sustaining that Japan traditional society stop them from widely experimenting with other blades in battle and they rather focus in just improving the katana like blade design they already have. And that resilience to change goes from weapons to, I don't know... rejecting chairs for centuries, for instance.

Now you claim that the "traditional" tanto shape was not about tradition but about the best answer for piercing and, at the same time, for using in everyday works, fine, and given that you say that shape was not designed either for seppuku then let's call this tanto the cooking-tanto.

Perhaps you're right, but just seeing how in Europe we have a specific weapon designed for every situation and even for every person, from rapier & dagger for unarmored duel to war hammers for piercing through solid armors, and even more than one weapon for a given situation... well, I just think that the Katana-like design for everything... even for cooking and daily labors! has to be a response to tradition.

Sure there might be some samurai not so traditional trying new things, in fact I heard about some using European armors that were given to them as a present (not sure if true though) but if you talk about European knights you have to ask when and where and circumstance to say what weapons he is using or even what collection of weapons might he be using, in a Samurai, generally speaking, Katana-like for everything.

So unless you think the Katana-like design is a kind of magic blade (and handle!) that excels at everything, you'll have to accept some degree of traditionalism for such a wide use in such a long time.

Michael Edelson test revealed that the katana he used did nearly as good as the longswords on a jack, despite not being handled in a half-sword fashion like the others, and not having a tip that is best for thrusting (as an o-kissaki for example). As for the rest I think I made my point (no pun intended).

Well, I finally checked Michael Edelson test. Here are his conclusions when testing for thrust:

Albion Regent, half-sword grip: easily penetrates.
Albion Talhoffer, half-sword grip: easily penetrates.
Katana, normal grip: penetrates, though not as easily. I’m not sure if it’s the point or the grip that made it harder. I would guess the grip.

I think this should end the discussion about what sword design is better for thrusting... If common sense, physics and geometry was not enough.

[Stacy Clifford]

I really think the argument about whether two edges are better for thrusting than one is kind of frivolous here. In reality you're looking at the difference between penetrating 3.5 inches deep vs. 4 inches deep in most cases. Both are enough to kill, and dead is dead; job done. All the weapons we're talking about have been proven wildly successful millions of times at doing the one job they were made for: killing human beings who were armed for combat. Unless Spanish burglars have taken up the habit of wearing armor, this is getting pretty irrelevant to the subject of the thread. Let's try to get it back on track or start a new thread for this topic. It makes more sense to discuss which weapons work best in a narrow hallway or provide a more well-rounded offense and defense than which one is going to make a deeper hole in a crook wearing a t-shirt.

By the way Francisco, the word you're looking for is "resistant" to change, not "resilient" (which means ability to bounce back). Just trying to help, your English is mostly very good.

[Francisco Urbano García]

I really think the argument about whether two edges are better for thrusting than one is kind of frivolous here. In reality you're looking at the difference between penetrating 3.5 inches deep vs. 4 inches deep in most cases. Both are enough to kill, and dead is dead; job done.

Well how about 0.5 inches vs 1 inch due to an armor, cloth... etc. Half inch is all you need to sever an artery, and that might be the difference between death and life.

Unless Spanish burglars have taken up the habit of wearing armor, this is getting pretty irrelevant to the subject of the thread. Let's try to get it back on track or start a new thread for this topic...

Oh now I think you have mistaken the threads, this one is the "why do you suppose..." thread that question straight blades vs curved ones. I think you refer to the "What's the best Sword for Home Defense"

By the way Francisco, the word you're looking for is "resistant" to change, not "resilient" (which means ability to bounce back). Just trying to help, your English is mostly very good.

Thank you Stacy for your comment, I know my English is far from perfect, but I was actually using resilient as "Capable of withstanding stress" meaning difficult to change its shape, thus "ability to bounce back" and such, when I said Japanese culture was resilient to changes I addressed Japanese culture ability to stand stress to cultural changes and keep basically the way it is through time... Bouncing back to its usual "shape" if you prefer.

But now I realize this expression is not very common in English and might induce to confusion, so thanks for the warning

[Jeremiah Backhaus]

It's a fact that rockwell hardness is in general, higher on japanese blades. Now it doesn't make anything better, nor does it mean that there weren't any exceptions (blade hardness was very variable in europe, I'm pretty sure it would have been in Japan too). All I said was that the different characteristic of each swords would tend to make them much more alike in their capacity than we would think. Michael Edelson test revealed that the katana he used did nearly as good as the longswords on a jack, despite not being handled in a half-sword fashion like the others, and not having a tip that is best for thrusting (as an o-kissaki for example). As for the rest I think I made my point (no pun intended).

I would ask for citation on this statement. Iron is not as hard as steel. The process of making a Katana utilizes more iron than steel. The Longsword of Europe utilizes more steel than iron. I agree completely that there is variation, mostly due to less advanced smelting technology. But the statement that the Rockwell of Iron is harder than steel, I'm not so sure that I can buy into that.

As to the spine lending hardness... I watched a show on (I believe) the discovery channel a while ago. I believe it was one of those "human weapon" kind of deals. In this show it had some model looking guy talking about how he loved the Katana, and it was "the best sword" (he did add "in my opinion"). During the course of the show he cut up a ballistics Gel form of a human, and at one point he thrust into it. This was shown in slow motion and was etched into my memory. The thing that I found so interesting was that the blade flexed laterally. What this impressed upon me was that not only was the force being off put in one direction, it was actually being lost in two! The Iron spine of the blade did not add rigidity that aided the puncturing capacity of the blade. Now, before the tangential topic of daggers and tanto come up, I am speaking of Katana and Longsword. The spine (as I saw) did not help. With the longsword, there is flex as well, in the lateral plane. Now the tempering of the WHOLE blade (not just the edge, as is the practice of Katana, as far as I know) makes this lateral flexing a good thing, because as the blade "springs" back to straight the penetration becomes more. Of course, I have not noted much of a flex at all (this was with an Albion Baron, a 13th century bastard sword, and a Brescia). The point (to use the image) is that the flex of a longsword is negatable, and if it were to be pressed would be a bonus to thrusting capacity. Whereas on a Katana the capacity is lessened on two planes because of the curve and the lateral flex. These statements are based upon my perceptions and testing.

The "Damascus" of either blade type does NOT impart some magical, mystical quality to the sword. It was simply a way to make a more unified billet with which to make a sword. Let us not buy into any mumbo jumbo about that.

Oh, and after test "cutting" a sword on an iron bar, a thrust from a quality European style sword on mail would not be as debilitating to the sword as put forth here. Any damage would easily be taken care of by a smith.

-Jeremiah (SA)

[Stacy Clifford]

Francisco, you're right, I did mistake this for the other thread. That's what I get for posting at 2am. And I understand your meaning now that you've explained it, but you're right, it's not a common phrase in English and it looked like you were just using the wrong word (although the basic meaning still came across). Sorry about that.

[Maxime Chouinard]

Perhaps you're right, but just seeing how in Europe we have a specific weapon designed for every situation and even for every person, from rapier & dagger for unarmored duel to war hammers for piercing through solid armors, and even more than one weapon for a given situation... well, I just think that the Katana-like design for everything... even for cooking and daily labors! has to be a response to tradition.

I see, you seem to think that the katana was the only weapon used back then. I think you would be surprised to see the panoply that was developped, even for dueling purposes. I could not possibly name them all, but you would have numerous different shapes of spears (yari), halberds(naginata), maces (tetsubo), war hammers (Die-tsuchi), flails (chigiriki), a variety of swords (nagamaki with or without crossguard, no-dachi, wakisashi, uchigatana, tachi), and weapons you wouldn't see anywhere else such as a mix between a scythe and a flail (kusarigama) or spears with a sliding tube to give it superior thusting speed (kuda yari). And I'm not even adding the matchlock, which shows by itself that Japan was not, before the Meiji period at least, a culture stuck in tradition, incapable of adopting or developping new ideas.

The sword was, as anywhere else, a backup weapon. An outside observer might think it didn't went through a lot of transformation as it retained it's curve and tsuba guard, but the fact remains that it did transformed a lot from the 8th to the 17th century, going from straight double edge to straight single edge, to long curved, to short curved, while developping double edged swords, longer ones, some with crossguards, and different geometries and moethods of construction. The european sword didn't changed that much either from roman gladius to the rapier. It mostly remained straight, double edged with a crossguard, with some variations in the shape or dimensions (I generalize here, but only to make a comparaison with the katana generalization). Could we say tradition? Maybe, both societies were traditional ones in essence until the 19th century. But in both case the design was kept because it was a polyvalent one, until it didn't suit the job anymore.

I would ask for citation on this statement. Iron is not as hard as steel. The process of making a Katana utilizes more iron than steel. The Longsword of Europe utilizes more steel than iron. I agree completely that there is variation, mostly due to less advanced smelting technology. But the statement that the Rockwell of Iron is harder than steel, I'm not so sure that I can buy into that.

As far as I know there is no iron (less than 0.2% of carbon per volume) in japanese blades, at least not good ones. There is, most of the time, a combinaton of two or three different kinds of steel, one harder, one softer, and a differential hardening to get the edge even harder. Here's the only article I could find on the subject, bear in mind it's very general http://swordforum.com/sfu/primer/heattreatment.html

The comment I made was based on my personnal experience while test cutting and thrusting with both european and japanese blades. during which the difference was rather evident.

As to the spine lending hardness... I watched a show on (I believe) the discovery channel a while ago. I believe it was one of those "human weapon" kind of deals.

I know what program you mean. The guy they used was trained in taekwondo, not any legitimate japanese school. The thrust he used was totally botched, and I don't know what type of sword he used, but I would guess it was a modern mono steel. I still do not think the curve (were talking a very subtle curve when the sword transformed into an infantry weapon, at some point it even got near perfectly straight) would be such a problem.

[Francisco Urbano García]

I see, you seem to think that the katana was the only weapon used back then. I think you would be surprised to see the panoply that was developped...

What would surprise me is samurai using them, I thought they rather use spears and crossbow and then katana-like swords for close combat. But if they also use regularly hammer, mazes, flails... so on, then today I learn something new Thank you.

The european sword didn't changed that much either from roman gladius to the rapier. It mostly remained straight, double edged with a crossguard, with some variations in the shape or dimensions (I generalize here, but only to make a comparaison with the katana generalization).

Well, now I think this is not right. I believe saying Japanese swords are curved single edge blades is a fair generalization. I mean, samurai had with their swords a nearly religious relationship (as far as I know... Bushido and staff) And they had a traditional relationship with their sword that Europeans didn't, making easier for Europeans to choose any blade that fits best his needs. Generalize European swords as straight double edge swords... well:

- Spanish Falcata: single edged inward curved blade.
- Geman Gross Messer: the closest european sword design to a katana?
- falchion, sabers... : single edged curved and straight

And all of them widely used...not rarities, for instance the falcata in Spain was the main sword used against the Roman Empire forcing them to upgrade their own weaponry to deal with that kind of "strange" swords.

So the generalization of European swords as straight double edge is a big no no. And unless you can give me another list of nice straight and double edge Japanese swords used by Samurai (perhaps you do and I keep learning ) I think that generalize their swords as curved single edged blades is just fair.

[Gene Tausk]

"The european sword didn't changed that much either from roman gladius to the rapier. It mostly remained straight, double edged with a crossguard, with some variations in the shape or dimensions (I generalize here, but only to make a comparaison with the katana generalization)."

Sir:

Saying that you "generalize" here is like saying the American dollar is the same as the North Korean won because they are both "paper money" and like saying there is no difference between an Uzi urban assault submachinegun and a 16th century matchlock because they are both "firearms" and like saying spear fashioned by a Neanderthal is the same as a 15th century English Bill because they are both "pole weapons." I can go on but I am certain you get the idea.

I sincerely and with respect state that you should do a modicum of research before making such an absolutely ridiculous statement. Your statement is so off-base and wrong I don't even know where to begin to address its mistakes nor will I waste my time doing so.

[Francisco Urbano García]

-error-

[Jeremiah Backhaus]

I would ask for citation on this statement. Iron is not as hard as steel. The process of making a Katana utilizes more iron than steel. The Longsword of Europe utilizes more steel than iron. I agree completely that there is variation, mostly due to less advanced smelting technology. But the statement that the Rockwell of Iron is harder than steel, I'm not so sure that I can buy into that.

As far as I know there is no iron (less than 0.2% of carbon per volume) in japanese blades, at least not good ones. There is, most of the time, a combinaton of two or three different kinds of steel, one harder, one softer, and a differential hardening to get the edge even harder. Here's the only article I could find on the subject, bear in mind it's very general http://swordforum.com/sfu/primer/heattreatment.html

The comment I made was based on my personnal experience while test cutting and thrusting with both european and japanese blades. during which the difference was rather evident.

As to the spine lending hardness... I watched a show on (I believe) the discovery channel a while ago. I believe it was one of those "human weapon" kind of deals.

I know what program you mean. The guy they used was trained in taekwondo, not any legitimate japanese school. The thrust he used was totally botched, and I don't know what type of sword he used, but I would guess it was a modern mono steel. I still do not think the curve (were talking a very subtle curve when the sword transformed into an infantry weapon, at some point it even got near perfectly straight) would be such a problem.

I kinda figured the guy doing the thrust was a hack. But it was all the experience of the katan thrusting that I was aware of. I admittedly have not worked with the katana, it holds no allure for me. I respect that it does to you. your knowledge of Japanese history is indeed very broad.

As to the carbon content in the blades. The books that I have that detail making a Japanese blade (either a katana or tanto) would be the books by Dr. Jim Hrisoulas. In that book he details the insertion of a steel sliver into an iron casing (now, today, getting your hands on iron is very difficult, so it would be a mild steel). Peter Johnsson also wrote something similar in an article for the guild of Saynt George publication "Dragon."

I will quote:
"When describing the quality of mediaeval European steel, weapons and armour one is often confronted with the belief that the contemporary Asian methods and results were vastly superior. This is a variation of reality based on myth, popular belief and misinterpreted facts. The methods of the Japanese sword smith resulting in a multilayered sword with a hard cutting edge and a semisoft back is just a way to match the slightly different demands that are a result of its intended use. The multiple layering in a Japanese sword is born of the necessity of making the steel more homogeneous and also a method to control the carbon content, just as was the case in Europe. In Japan this was pursued to an artistic level of craftsmanship and the structure, the watering of the surface, was a much appreciated effect. The ideal of the patterned surface was abandoned during the 11th century in Europe, when better methods of processing iron resulted in more homogeneous steel."

A little later:
"The sharp edge of a Japanese sword is made possible by the high hardness in the thinner part of the blade. To avoid having the blade snap in use, the body of the sword is left semisoft. The consequence of this is that a Japanese sword might bend if a cut is not clean and precise. The hard edge can also be prone to chip. "

It is important to include:
"It is a futile task to try to find sword when comparing different cultures and periods. Weapons are shaped according to intended use and should be viewed from that perspective. Only by doing this a better understanding is achieved."

According to Mr. Johnsson, the spine of the katana is left semisoft. This could mean that the tempering is not carried through to the spine, it could mean that the case hardening is only on the edge, leaving the carbon lower spine to a softer degree.

As I said before, I am not interested in the katana. My best friend in High School was. While hanging out with him, I was forced to learn a bit about the sword itself. As a blacksmith, the steel and construction were of interest to me. There will necessarily be a variation to these statements of Mr. Johnsson. Peace time experiments with the katana yielded a spectrum of swords. I don't think that I am going too far by saying that because there is a piece that is extant, it does not mean that there was a larger spectrum that yielded the same quality.

I appreciate the article on tempering. But the citation that I was asking for was for the statement that the RC is higher on katana as opposed to the longsword. Are you speaking of the edge or the spine? Thank you for your participation. I hope it comes as a scholarly, friendly debate.

-Jeremiah (SA)

[Maxime Chouinard]

Well, now I think this is not right. I believe saying Japanese swords are curved single edge blades is a fair generalization. I mean, samurai had with their swords a nearly religious relationship (as far as I know... Bushido and staff) And they had a traditional relationship with their sword that Europeans didn't, making easier for Europeans to choose any blade that fits best his needs. Generalize European swords as straight double edge swords... well:

The "religious" aspect only came about during the Edo period when it became somewhat of a status symbol. Before that, a man who could pick up a sword could own one, so it was not regarded the same way. Even during the Edo period, various classes could carry swords, the bushi class was special because they could wear both the long and short swords. The european martial arts are not the only ones who have myths to deconstruct .

As for the generalisation about the European swords:

Saying that you "generalize" here is like saying the American dollar is the same as the North Korean won because they are both "paper money" and like saying there is no difference between an Uzi urban assault submachinegun and a 16th century matchlock because they are both "firearms" and like saying spear fashioned by a Neanderthal is the same as a 15th century English Bill because they are both "pole weapons." I can go on but I am certain you get the idea.

I sincerely and with respect state that you should do a modicum of research before making such an absolutely ridiculous statement. Your statement is so off-base and wrong I don't even know where to begin to address its mistakes nor will I waste my time doing so.

Sigh... I kinda knew I would have to explain this.... I said "I generalize" not because in general European swords are all the same. I used the word to denote that someone could also describe the European sword as such a stereotypical way, not considering all it's variants and evolutions, the same way that could be done with a katana. In the public mind there is one shape that comes up when you mention a japanese blade and one for the European sword. Are they accurate, no, they're not taking into account the wide array of possibilities that was possible then. Am I making more sense and sounding less stupid?.... Hope so.

The English language is not my first one and I sometimes get a hard time exposing my ideas as they should be.

According to Mr. Johnsson, the spine of the katana is left semisoft. This could mean that the tempering is not carried through to the spine, it could mean that the case hardening is only on the edge, leaving the carbon lower spine to a softer degree.

It's actually one way of doing it, a popular one today I might say, but not the only. There are configurations that used an overall hard shell with a softer center, other use a hard edge with medium sides and soft center, other use an overall medium blade (I suppose it would have been the case for munition grade swords) or even a complicated combination of the three. As for tempering it is done on the whole blade, but some elements are tempered more than others by the use of clay coating.

During the Edo period, other types of steel began to be used, one that was even harder (and thus more prone to damage) than was used before during the warring states (a period in which european and Indian steel was also used). For some reason they don't fully understand the old steel well, and people nowadays still use the "new" steel as it gives a more aesthetically pleasing aspect to the blade.

[Jeremiah Backhaus]

According to Mr. Johnsson, the spine of the katana is left semisoft. This could mean that the tempering is not carried through to the spine, it could mean that the case hardening is only on the edge, leaving the carbon lower spine to a softer degree.

It's actually one way of doing it, a popular one today I might say, but not the only. There are configurations that used an overall hard shell with a softer center, other use a hard edge with medium sides and soft center, other use an overall medium blade (I suppose it would have been the case for munition grade swords) or even a complicated combination of the three. As for tempering it is done on the whole blade, but some elements are tempered more than others by the use of clay coating.

During the Edo period, other types of steel began to be used, one that was even harder (and thus more prone to damage) than was used before during the warring states (a period in which european and Indian steel was also used). For some reason they don't fully understand the old steel well, and people nowadays still use the "new" steel as it gives a more aesthetically pleasing aspect to the blade.

Keeping in line with a scholarly debate, I want to establish a point that is being debated. My point is: the style and steel, in general (meaning the most common), of making a katana is such that allows more bending of the blade; and if there is more bending, the supposition laid out earlier, namely that a katana has a higher Rockwell hardness than a longsword, is not true.

Now, I have cited and quoted a world renowned sword smith to back my point. And to this you have said that the Edo period brought advancements in metallurgy. I would like to see some citations, please. I do not know when the Edo period was, so that does not help to prove anything.

You mentioned that there are different styles to making the blade. I allowed for that in my post. But one extant piece does not make it the norm practice. Call it munitions or what you will, but the run of the mill sword is going to have the most common way of making and will display the characteristics that are essential to the usage of the blade (ideally).

You mention an overall casing of higher carbon steel. This is called "Case Hardening" this does not provide much in the way of stabilization for the item case hardened. It also tends to be a bit hard to control as any air contact during the hardening will cause the carbon to be thinner on the point of contact.

As for tempering, the blade was tempered, specifically the edge. If it were a semisoft steel or iron, it would not be tempered, it would be annealed for the qualities that would be desired. I again reference you to the quotes from Mr. Johnsson.

As for the old and new steel bit, I don't know what you are talking about or who "they" are. But if you are calling Mr. Johnsson's understanding of steel and blades into question, go to www.albion-swords.com. That gives a bit of his credentials. And then try and get your hands on Svante, then you will be certain that he knows what he is doing.

At any rate, I would ask again for references on the Rockwell statement that you made, Mr. Chouinard. And I would also ask that you reference a bit more so that the debate may continue in a scholarly manner. And let us not move into the fine artistic examples that are possible, let us stick to the grade of weaponry that could be found on the battlefield, that was made for it. Pieces in peacetime, from both countries will have beautiful pieces that will only serve to drag this discussion away from a possible outcome.

Final question: At which part of the blade are you saying the Rockwell is higher? Overall, Spine, edge, middle? That might help here.

-Jeremiah (SA)

[Stacy Clifford]

I agree with Jeremiah that a few reference notes for those of us who aren't as familiar with Japanese history would be helpful in this discussion. No need for excessive detail, but I don't know when the Edo period was either (sometime after the Cretaceous, I presume).