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Saint Augustine, Northeast Florida
Going public with archaeology for outreach, assistance to local governments, and service to the citizens and state of Florida. Visit our website at: http://flpublicarchaeology.org/nerc/
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Archive for February 2016

Park Pick: Blue Spring State Park

Park Pick: Blue Spring State Park

"Please Take Nothing but Pictures; Leave Nothing but Footprints"
The beginning of the boardwalk trail at Blue Spring State Park. 

It was an absolutely beautiful day outside today in Central Florida! I decided to take full advantage of the beautiful weather and pay a visit to Blue Spring State Park in Orange City. This Park truly has it all: beautiful natural landscape, a great historical site, and archaeological significance. I am excited to be able to share a little bit about the Park with you for this "Park Pick"!

Peering down from the boardwalk into the clear blue-green water of the spring. 

Blue Spring State Park is a gorgeous example of natural Florida landscape. The park features a crystal-clear spring that flows into the St. Johns River. The constant 73-degree temperature of the spring’s water make the spring a favorite winter haven for manatees. Although the spring is open for swimming in the summer, the Park closes swimming access in the winter to make way for these gentle giants. According to the Park’s website, hundreds of manatees can be viewed from the boardwalk that spans the length of the spring. Today was no exception; take a peek at this lovely little guy who swam right up to the boardwalk to take a breath of fresh air!

Hello little manatee! 
In addition to being stunningly beautiful, Blue Spring State Park is a significant historical and archaeological site. I was fortunate to be able to check out The Historic Thursby House on my visit. In 1856, Louis Thursby, a former gold-rush prospector who turned to growing oranges, purchased Blue Spring and moved into the area with his family. Thursby’s “Blue Spring Landing” became a prosperous steam-boat landing that aided in moving tourists and trade goods around Florida. The Historic Thursby House was constructed in 1872, on top of a Native American shell mound. Visitors to the park can walk through the first-floor of the historic house for a self-guided tour.

The Historic Thursby House was built in 1872 by Louis Thursby.
The House sits on top of a prehistoric Native American shell mound. 
Inside the Thursby House, visitors can read about the Thursby family and see various antiques, historical records, and artifacts from the site.

A wood-burning stove inside one of the first-floor rooms within the Historic Thursby House.
A lovely display of fine dishes on display within The Historic Thursby House.

      The Precolumbian mound known as the Thursby Mound at Blue Spring is a "truncated cone" that measures thirteen feet high and is approximately 90 feet in diameter. Excavations by archaeologist C.B. Moore in the nineteenth century demonstrated that the mound dates to the St. Johns IIb period (A.D. 1050-1513). Some of the artifacts discovered at this site include plant and animal effigies and a number of unique and unusual vessels. During the St. Johns IIb period, a shell causeway would have led from the mound to the St. Johns River. (Milanich, 1994). 

A framed poster near The Historic Thursby House shows examples of the artifacts that were recovered during archaeological excavations in the area during the nineteenth century.

  After visiting The Historic Thursby House, you can walk along the boardwalk which leads all the way up to the head spring. It is a great walk, most of the the boardwalk is covered by natural Florida hammock. Informative covered posters punctuate the walk, providing information to curious visitors about the history of the area, the wildlife that can be observed there, and the natural mechanics of the spring itself. 

This trail is a nice walk through natural Florida hammock and leads to the head spring.

This picture hardly does justice to the beauty of this park!
This was taken from a landing that connects to the boardwalk trail. 
Hello little guy! This raccoon was hanging out just below the boardwalk I was on. 
     After this Park visit, I was reminded once again that Central Florida is full of historical and natural treasures. I highly encourage anyone who has a free afternoon to check out this lovely park and to read up on Central Florida history to learn about the early settlers within the region.


For information on the park: 

For information about the Thursby House: 

The Historic Thursby House in the media (short article)

To learn more about the Native Americans who lived in this region during the St. Johns IIb period and beyond, check out the book "Archaeology of Precolumbian Florida" by Jerald T. Milanich.



References:

https://www.floridastateparks.org/sites/default/files/Division%20of%20Recreation%20and%20Parks/documents/bls-brochure.pdf

Archaeology of Precolumbian Florida. Jerald T. Milanich. Gainesville, FL: University Press of Florida. 1994

Where The Boys Were...

On any given day, FPAN staff can be seen in libraries, schools, archaeological sites, or driving.  But, there is an actual physical office in the Northeast Region where they sometimes reside; It is located in an old billiard building on the campus of Flagler College in St. Augustine, FL.

Currently known as The Markland Cottage, the building was originally the "man cave" for Dr. Andrew Anderson and his male guests.  Between 1899-1901, Dr. Anderson and his wife Elizabeth transformed his family's antebellum citrus plantation into something more fitting for the Gilded Age.
Being that Dr. Anderson's home was located next to Flagler's grand Ponce De Leon Hotel (now Flagler College), perhaps he felt some pressure to take it up a notch.  
Markland House (Image: hcap.artstor.org)
While transforming their primary residence (The Markland House), several outbuildings were also created. One of them was the "gentleman's billiard building" located down a palm-lined path directly behind the main house. It made for a quick post-dinner get away, allowing the men to  play billiards, drink brandy and smoke cigars away from the prying eyes of their women.  (Ironically, this  testosterone haven is now an office comprised of all women).
Markland Cottage aka: Gentleman's Billiard Building

Cigar smoking was clearly a favored activity since the building was designed to release the smokey air.  The convex ceiling had an opening in the center with a louvered shutter.  Ropes could open the shutter to allow the smoke to escape through the roof.  The shutters were then covered with a beautiful basket-weave wood panel (this is a "gentleman's" man cave don't you know!)   The hole and the shutters no longer exist , but the panel still remains.
original basket-weave panel

And if you require additional evidence of their love of cigars.... 
cigar burns on floor
Many passers by stop-in to admire Markland Cottage's unique features such as its front porch palm log columns...


and its majolica fireplace with beautifully reproduced hand-made tiles...


We also get people stopping in who remember teaching or taking a class here in the earlier days of the college.  Others remember when it was relegated to a storage shed and eventually over-taken by vermin and termites. 
Stripped - "Before shot" (Image: BTS Builders, btsbuilders.net)

In 2005, Flagler College, with assistance from a State Small Matching Grant-in Aid, rehabilitated the building.  It was painstakingly restored to much if it's original charm.  We would love to give you a tour of our digs if you stop by (It's only one room so it's a short tour!)
"After shot"

The gentleman's billiard building has proven to be a snug, but ideal office for the FPAN Northeast Staff. 
The location of the ladies' billiard building is yet to be found...


Text and images: Robbie Boggs, FPAN staff except where noted

Metal Detecting and Archaeology

Metal detectors can be a great tool to help archaeologists identify metal artifacts, especially at sites like battlefields where artifacts are small and widely distributed. Doug Scott was one of the first archaeologists who used metal detecting at the Battle of Little Bighorn. He used these tools along with archaeological survey methods (especially mapping and spatial patterning!) and forensic methods (like figuring out bullet trajectories) to understand how the battle unfolded. This method has been repeated at many other battlefields very successfully.

So I was very excited to attended the Advanced Metal Detecting Training for the Archaeologist training, offered through the Register of Professional Archaeologists and taught in part by Doug Scott! Over three days, we learned how to use metal detectors and even completed a small survey near Fort Pickens at Gulf Islands National Seashore.

We spent the first day in the classroom, learning how metal detectors can be used on various projects, how to set up and document surveys and the basics of the equipment. Did you know the first metal detector was invented by Alexander Graham Bell? He was asked to use it after President Garfield was shot in order to find the bullet more quickly and efficiently. However the detector couldn't seem to locate the bullet, as it kept going off whenever it got near the President. No one had warned Bell that President Garfield was lying on a new metal coil spring mattress!

Metal detectors work by sending a electromagnetic wave into the earth that responds to anything magnetic within range. Some models can discriminate between types of metals while in the ground. The machine's depth range can vary but many range between 10-30 centimeters. You can even get an underwater metal detector to help in excavating sites like shipwrecks!

Metal detecting is no joke: we spent a whole day learning the basics before we even picked up the equipment.

To practice and hone our new skills, we were able to do a small survey of an area hoped to be associated with a Civil War battle near Fort Pickens. Our first step was to understand the background and history of the site, which included a great tour of the Fort by the Park Historian. During the Battle of Santa Rosa Island, Confederate troops attacked a group of Union soldiers who were camped outside of the fort in efforts to capture the Fort. The Confederates were unsuccessful and soon retreated, but not before burning the camp and taking a few casualties.

Understanding the history of the site is step one to any survey.
Our small survey did find evidence of this Civil War camp, including buttons, ammunition and other related military items. We found a large hunk of melted lead that could have been a melted box of ammunition, which speaks very much to the tale of a burning camp. And of course, we also found lots of more recent finds including pop-tops, more recent gun shells and various bits of metal trash.

The FPAN Crew and Lauren Walls, AMDA instructor, with metal detector find. Photo Credit: Doug Scott.
For more on metal detecting, including case studies and a few notes on laws and ethics, check out Time Team America's blog on the topic.


Text by Emily Jane Murray, FPAN Staff


Photogrammetry Basics

A Quick Overview of Processing Pictures Into a 3D Model

Screenshot of a 3D model of tabby slave cabin foundations and walls from Kingsley Plantation, Florida.

Photogrammetry,as a technique to create three-dimensional models, is a growing trend in heritage management and a new tool in the archaeologist's toolkit that is allowing for quick, accurate data collection; this digital data is easily stored and shared, making it one of the best methods for disseminating information about artifacts, historic structures, or even entire archaeological sites. This post will highlight a few of the useful software programs that you can use to create 3D models as well as a an example step-by-step of the creation of a 3D image.


At the most basic level, photogrammetry is the use of photographs to determine some kind of measurements from them. This has been a field of study since about as long as photography has been in use, gaining more momentum as portable cameras were able to be flown on aircraft. Today, photogrammetry might be a word that is applied to a number of specific techniques for remote sensing and measurement data obtained through photographic techniques whether on the ground, in the air, or even from low-earth orbit. For those of us in the field of archaeology, however, we are most often hearing the word these days in relation to software that allows us to create 3D digital models from a series of pictures. 

There are several types of software to choose from. FPAN does not endorse any particular one of these software packages. Some are open source, some are just free; for the most part it's a matter of defining your desired outcomes and matching it to the program that best fits your data collection needs. The example below is produced with Agisoft Photoscan's Standard Edition. We have found that it is a great package and gives excellent results-it's pretty easy to use once you get the hang of it, too! A few other examples of software packages/equipment that are used for this and similar purposes include:

Autodesk 123D Catch
Structure Sensor
Autodesk Recap
Acute 3D Context Capture
Drone Deploy
Blender
Sketchup
and, though not exactly in line with what we're talking about ArcGis Earth has some neat 3D things you can create/work with.

This example will serve as a general overview of the process, just to give you an idea of how this kind of software works.

The first step is to take a series of photos of an object. Generally, there should be a 60% overlap of the pictures to allow the software to tie the pictures together. You can either move the camera around the object or move the object around in front of the camera. This sounds a little bit easier than it actually is. The outcome of your model will depend on your photo set. The better the quality and number of pictures, the better the model. It can also help to have reference points included in the picture, say lettered numbers, pin flags, or other objects; this all helps the software align the photos.

Photos are taken from as many angles as possible, making sure to overlap. This wasn't hard to overlap as every photo overlaps due to the size of the headstone.


Once you have taken the pictures and uploaded them into the program, the next step is to "align" the photos. Don't worry, the program does this for you. It may not be able to align all of the photos, which is why more is better. However, as with all software programs, the more data you give it to crunch, the longer it will take. This will create the "sparse point-cloud" which will give you some idea of what camera shots were able to provide data and a first step to edit a little bit.

The sparse point cloud is generated by aligning the photos. The blue rectangles are the locations of the camera when it took the picture. You can see some random points outside of what we are trying to model.


After the photos are aligned the next step is to create a "dense point cloud". In essence, the program is defining x,y, and z coordinate locations in a space of the object you have taken a series of pictures of. This is the big framework that the rest of the model will be built on, and an opportunity to edit errant points or clear out photographic "noise" like other objects you are not intending to model.

The dense point cloud has been created. It allows for a much better visualization of what you might want to edit out and what you want the program to focus on during the next steps.


Once the dense point cloud is set to your liking you will then create a mesh frame for the object; this is sort of like connecting all the little dots together into the basic outlined structure. This gives the object shape and at this point is not just a point cloud, but a 3D object.

Those of you familiar with GIS might recognize these little triangles. This is the mesh that has been generated by linking the dense cloud points together.


Finally, the color texture is overlaid on top of the mesh framework. A few more tweaks here and there and you have yourself a brand new 3D digital model that you can then upload, share, and even let other folks download to print on a 3D printer!




There are many options for photogrammetry processing out there and a multitude of uses. We'll have more in future posts, but hope this brief introduction helped you better understand how this process works.

Be sure to follow FPAN on Sketchfab to see our projects!

Text and pics: Kevin Gidusko

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