Mythbusters and Cannons

The November 11, 2012 Mythbusters probably elevated what must have been an obscure myth (I never heard it before) into common knowledge. They have done this before. Their pirates wearing an eyepatch to see in the dark is the most infamous example. They also repeated the idea that you never use the edge of a sword to parry a cut (this rule is pretty much limited to 15th century two-handed swords).

In this case the idea is that in the 15th century they used stone cannon balls so that the enemy could not gather up spent balls and return fire with them. Their testing showed that a granite ball will do comparable damage to a steel ball but will shatter so that it cannot be reused. There are numerous problems with their testing and methodology.

They did their testing against "castles". That means that we are talking about siege pieces instead of field pieces. They did their testing with "Old Moses", a field piece. This is important.

Cannons were rare in the 15th century. Siege pieces were often made specifically for the siege. They shot large balls. One of the surviving 15th century siege pieces, the Great Turkish Bombard, fired balls that were nearly two feet in diameter.

Think about this. There was no standard bore since all of the cannons were custom-made for the occasion and they were used as siege pieces meaning that they were fired at the walls of a castle or city. But the myth assumes that the defenders just happen to have a cannon that uses the same size ball, that they have plenty of powder but have run out of cannon balls, and that they are willing and able to open the gates and rummage around looking for 2-foot balls of iron that they can carry inside. Plus there is the assumption that the iron balls would still be usable and retrievable.

Every part of this myth is preposterous. Even during the Spanish Armada in the 1580s, Spanish cannons were so unique that some ships had to quit firing before they ran out of powder because the only cannon balls left were for the wrong side's cannons.

During a siege, gunpowder, not balls, were normally what was in short supply. Since the attackers were normally entrenched, there was little for a siege gun to fire at, anyway.

Stone balls were used because:

1. Siege pieces like the Great Turkish Bombard were not well made and needed to launch a lighter projectile or risk exploding.
2. Stone was cheaper than iron. Iron casting technology was still in its infancy. The best cannons were made from bronze or brass but these metals were too expensive to use for ammunition. The Great Turkish Bombard is bronze.
3. Siege engineers were used to launching stone balls since they had been used for centuries in trebuchets.

This episode made the news when a stray cannon ball bounced off of a backstop, went through three houses, and landed in a car. This happened when they added extra powder to a short, home-made cannon to see if they could get it to shoot at the same speed as Old Moses. The footage of the short cannon being fired shows that the muzzle was elevated even though it should have been firing point blank (no elevation). This probably contributed to the accident.

At times the team congratulated themselves for being the first people in five hundred years to fire a stone cannon ball. Actually, they were not even the first ones on the show to fire one. A stone ball was used when they made a cannon from a tree. Jamie retrieved the ball and used it again.

None of this has anything to do with the the Golden Age of Piracy but I know I am going to hear about it every time I bring out my cannon. It is going to be worse on the Santa Maria where we have stone balls to reduce breech pressure.

The Bounty Abandoned

The crew of the HMS Bounty had to abandon ship during Hurricane Sandy. Of the 16 member crew, 14 have been picked up by the Coast Guard after taking to the lifeboats. Two are still missing. Earlier reports had said that there were 17 crew members.

The ship had been on route from Connecticut to St. Petersburg, Florida and had tried to go around the storm.

The last anyone knows, the ship was still intact and floating.

The ship was built for the 1962 movie Mutiny on the Bounty. It was supposed to have been burned at the end of production, just as the original was, but star, Marlin Brando, refused to finish the movie unless the ship was preserved.

It has been in a number of other movies since then including PoTC: Dead Man's Chest.

I went through it last Summer when it participated in Opsail 2012. A crew member admitted to me that the copy is a bit bigger than the original in order to accommodate the film crew.

UPDATE: The 15th member of the crew was found but did not survive. She was Claudene Christian, age 42 and a relative of Fletcher Christian from the original Bounty.

Captain Robin Walbridge has not been recovered yet.

The ship itself sank in 18 feet of water and its masts are still visible. Hopefully it can be raised.

Navigation and the Parallel Ruler

One thing that I seldom see in navigational displays (including mine) is a parallel ruler. This was indispensable.

The parallel ruler is a pair of rulers connected by a pair of bars. The bars let you move the rulers apart but always keep them parallel.

In order to get from one place to another you need to know what course to use. One way to do this would be to use a protractor but period mapmakers usually provided ways of figuring your course without this. These require a parallel ruler.

One way was to include a compass rose on the map. You would mark the direction you need to follow then walk the ruler up to the compass rose to see what heading that corresponds with.

Period navigation was known as "loxodronic". Lines known as "loxodrons" would be drawn on the maps, usually in open spaces. These were conveniences and corresponded to headings. You lined up the course you needed to take then walked the parallel ruler across the map until you hit a corresponding loxodron. You then took your heading from the loxodron. These are longer than a compass rose and easier to match with.

Skull and Bones by John Drake

John Drake set himself the task of writing the backstory of Treasure Island, answering such questions as "who was Captain Flint?" and "Where did the treasure come from and why is it buried on Treasure Island?" This was spread over three books: Flint and Silver, Pieces of Eight, and Skull and Bones.

Flint and Silver introduces us to the characters. By the end, Long John Silver is marooned on the island along with a crew. In Pieces of Eight, Silver's crew fortifies the island for Flint's inevitable return. By the end of the book, Silver is in possession of some of the treasure, the ship the Walrus, and his beloved wife Selena. Flint is in custody of the Royal Navy.

Skull and Bones picks up from there. The book has many twists as Flint, Silver, and Selena take separate journeys that all lead to London then to Annapolis and Savannah. It is the weakest of the three with no strong plot. It is more like one thing after another. It also lacks any exciting battles. There is a battle at the end but the lead characters are more spectators that participants.

Of the three books, Pieces of Eight (the middle one) is the strongest. While it has many twists and turns, it also builds to the inevitable confrontation on the Island. It is possible to read this one separately from the others.

All three books are well-researched and written in a style that sounds both old-timey and nautical. They are eminently readable. I recommend all three.

Navigation in the Golden Age of Piracy

I've been doing presentations on navigation for twenty years but I seldom have enough time to get into the details. It has been a while since I have posted more here than just even write-ups so I am overdue for something with some meat on it.

Navigation breaks down into three parts - figuring where you are going, recording where you have gone, and computing where you are. All of this applies to open water navigation. Simply following the coast does not require any special skills or knowledge.

The first part of navigation is known as "loxodromic navigation". This consists of figuring the proper heading to get from one point to another. To sail from New York to London you sail at 73 degrees. Since period compasses had 32 points instead of 360 degrees, this meant sailing East-northeast.

Loxodromes are also known as rhumb lines.

Because maps are a flat projection of a round surface, getting the rhumb line correct can be difficult. Also, maps of the period were not particularly accurate so you might sail to the proper place on the map and discover that you are still in the wrong place. My navigation display includes a map of the Atlantic in which Florida is too small and at the wrong angle. Anyone sailing for Florida using this map would hit land far east of where it shows.

In general, large scale maps were worse than small scale ones.

In addition to these problems, the wind seldom cooperates. Chances are that you will not be able to sail a direct course to your destination. That means that you have to keep track of where you have gone in order to figure where you are. This is known as "dead reckoning".

There are special tools used for dead reckoning navigation. The first is the sand glass. This is a half-hour glass. Every half hour it is turned and the current speed and heading are marked. A board called a "traverse board" was used for this. It had a face that looked like a compass with eight concentric circles of 32 holes (256 holes total). The first time the glass is turned a pin will be placed in the innermost hole corresponding to the current heading. The second ring of holes is used for the next reading and so on for eight turnings of the glass.

At the same time the ship's speed would be measured by throwing the end of a knotted line overboard and timing it with a small sand glass. When the glass ran out you would count the knots that had unspooled. Nautical speed is still called "knots" because for centuries it was measured by knots in a string. There was a scale for recording this at the bottom of the traverse board (to save space it was usually two scales of four hours each). At the end of a four hour shift the board would have eight measurements. These would be recorded for the navigator. He would then plot out the position on a chart.

The navigator would also have to estimate drift. This was done by dropping a weighted line in clear water and seeing how much it bowed away from straight. There were no tools to help with this. It had to be done by eye and experience.

All of this gave crude approximations and in heavy storm sailors often stopped measuring speed or direction. A navigator could check his calculations using the sun and the stars. There were several tools that could be used for this including the quadrant, the astrolabe, the cross staff, and the backstaff (which was only suitable for measuring the sun). None of these could give longitude (east and west), only latitude (north and south).

Sighting the North Star was the easiest. Whatever angle it is at is your latitude. But it is a star and harder to see in clouds or a haze. Also, as Columbus noted, the North Star moves slightly during the night.

Finding the latitude with the sun requires several sightings taken around noon. The highest one is local noon. This angle is subtracted from 90 (because it is relative to the equator instead of the north pole). The high point of the sun moves from one day to the next as the Earth tilts on its axis. Twice a year on the equinox the sun is directly above the equator and no other measurements need to be taken. The rest of the year the navigator needs an almanack. This gives the correction for the date but it requires the navigator to know the approximate latitude. After this correction has been applied then the navigator has his latitude.

It was notoriously difficult to get a good reading on the sun or the north star while on a moving ship. Because of the crudity of the instruments, latitude figured on dry land could be off as much as 80 miles. On a ship that could be 300 miles.

There were other ways of checking your location. Islands often have clouds hanging over them that can be seen even when the island itself is below the horizon.

The sea bottom can be a source of information if it is shallow enough to measure. Depth was measured with a sounding lead. This was a long piece of lead attached to a long rope. The rope was marked at six foot intervals with standard markings. The first fathom was normally a leather strip with two ends. The second one had a leather strip with three ends. The third one had a white rag. The fourth had a red rag. Etc.

The bottom of the sounding lead had a hollow spot that was filled with brown tallow (meat fat). Just before the lead was dropped a fresh coat of white tallow would be applied. This is soft and sticky enough to bring up the soil from the bottom.

A detailed chart would indicate what sort of bottom was in different areas and indicate the depth.

Even if you were out of sight of land you might discover some useful information. Rivers will deposit silt miles from land so they can be detected while in open ocean.

Even with all of these tools, navigation was a hit-and-miss art. Some navigators would play it safe by going to the correct latitude first then sailing east or west to their destination. This was an opportunity for pirates. They could increase their chances of finding prey by cruising back on forth along well-traveled latitudes.

Michigan Pirate Festival

The Michigan Pirate Festival was last week. It is actually multiple events. The first happens at the public library and runs Monday through Friday. This was a highly successful, kids-oriented event. There were long lines each day and thousands attended. Late Friday afternoon has a "pirate sail-in". The sail-in had to be cancelled this year because of bad weather. Waves ranged from 4' close to shore to 5'-7' further out. It was also raining much of the day.

On Saturday and Sunday the festival moved and expanded to Harbor Island. This is the part that we participated in.

The festival was set up as a large square. A timeline of historic pirates was on one side. The far side featured ren-fair pirates. The isles in-between had vendors. The middle of the square was devoted to entertainment, much of it kid-oriented.

We were set up beside the Forsaken. We brought my boat the Firefly which was mounted with my swivel gun. I also brought my cannon, a navigation display, and some weapons. Beside us was Mission the Pirate-Surgeon with his ever-popular display of early 18th century medical equipment. The Forsaken had a large set-up with a tavern, their gibbet and pillory, and a couple of other tents.

Across from us was Shenanigans in Leather with SOS Boss doing their own kids' activities.

Further down in the other direction was a different pirate display, some Civil War "pirates", a viking, a Corsair, and some Romans. The Romans brought some siege equipment and a cross. They were big on crucifying people. They even crucified Tinkerbell a couple of times.

The kids area included some famous literary pirates such as Captain Hook who was accompanied by Peter Pan and Tinkerbell and the Dread Pirate Roberts who was accompanied by Princess Buttercup. There was also story-telling, a puppet show, and a trio of mermaids in kiddy pools. There was also a pair of Captain Jack Sparrows (not counting the Jack Sparrow puppet).

Beyond that was a stage that featured fire dancers and an abbreviated Romeo and Juliet. The dancers were accompanied by a couple of electric guitars and a drum set.

Over in the corner was a tavern with what sounded like a decent Irish band. I was too busy to go over and listen to them.

Saturday was cool, sunny, and windy. We brought a shade fly for Mission but the wind pulled the stakes out of the ground (which was still soft from the previous day's rain) and we gave up. We did get the fly to stay up on Sunday which was a little warmer but overcast with less wind.

There was a rather confused battle both days. This involved some of the pirates taking Caesar captive and his being saved by the Forsaken. We were on the same side as the forsaken so we hauled the cannon and the boat to one end of the field (the swivel gun was still mounted on the boat). The other side had a Civil War cannon.

The battle started with Tinkerbell delivering a message to Caesar who had her crucified for her efforts. She probably gave some kids nightmares on Saturday with her acting although once she was up on the cross she said, "I can see my house from here."

After the end of the battle on Saturday the Romans demonstrated their siege equipment. The "Medieval" trebuchet was less than impressive although a different weapons whose name escapes me was able to send an arrow an impressive distance.

On Sunday they fine-tuned the trebuchet and launched some mellons. One wild shot nearly dropped a mellon of Mad d'Dogg. The final one went straight up and almost hit the trebuchet.

We had a stead stream of people although the festival never seemed crowded. We heard on Sunday that 4,000 people had attended on Saturday. I'm sure that the Sunday attendance was at over 2,000.

The festival itself was enjoyable and most of the people who had been at Put-in-Bay were there so we had plenty of friends with us.

Mermaids

I watched Pirates of the Caribbean 4 - On Stranger Tides again last week. That and some news articles on the popularity of mermaid tails got me to thinking about these creatures.

These days we think of mermaids as friendly and human-like. Disney's Little Mermaid acts just like any teen-age girl.

The mermaids in PoTC/OST are different. Grown men throw themselves into the sea rather than face the mermaids. It turns out that they have good reason for this behavior. With the exception of Barbossa and a small landing party, the entire crew is killed by the mermaids.

The mermaids of legend were not much better. They were not as direct but they were often sirens, luring ships into shallow waters where the ship would run aground and its crew would drown.

Other times they were simply a bad omen. Seeing a mermaid meant that you were in danger (possibly because they liked the shallows). Blackbeard seems to have believed this. According to Wikipedia:

The logbook of Blackbeard, an English pirate, records that he instructed his crew on several voyages to steer away from charted waters which he called "enchanted" for fear of merfolk or mermaids, which Blackbeard and members of his crew reported seeing.

Anything that Blackbeard was wary of was dangerous, indeed.