Our next foray in the world of technology was incorporating laser scanning in order to document remains of the slave quarters at Chocolate Plantation. The Plantation is located on Sapelo Island in Georgia.  

        The name "Chocolate" was derived from the Native American village of Chucalate (Honkerkamp & Devan, 2). The first residents were Spanish Missionaries in the 16th Century (Honkerkamp & Devan, 2). It is believed that the area was occupied as early as the 18th Century (Honkerkamp & Devan, 2). Mary Musgrave and husband, Thomas Bosomworth claimed the island through a dispute with the local Indian chief Malatchi (Honkerkamp & Devan, 2). Though the couple was unable to prove ownership to the British aristocracy, Musgrave and Bosomworth still sold the property to a London salesman by the name of Isaac Levy (Honkerkamp & Devan, 2). 

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           There are many uncertainties surrounding the circumstances of the Levy transaction. The Crown never officially accepted this transaction and the land was sold in a public auction in 1759 (Honkerkamp & Devan, 3). The island would change hands many times over the next century but no official owner appears on record until 1793 when it is purchased by Louis Harrington (Honkerkamp & Devan, 4). Harrington used the island for plantation land with a total of 68 slaves until he sold it in 1801 (Honkerkamp & Devan, 4). The island was sold to Richard Leake and his son-in-law, Edward Swayback (Honkerkamp & Devan, 4).  However, soon Leake would pass away and leave the land to Spalding (Honkerkamp & Devan, 4). It is around this time that Swarbeck sold half of the land to Thomas Spalding (Honkerkamp & Devan, 4). The property was leased to a Richard Hopkins for three years and was then taken over completely by Spalding in 1808 (Honkerkamp & Devan, 4). 

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           It is this time in the history that the tabby slave cabins were erected on the property (Honkerkamp & Devan, 4). Tabby is a mixture of equal parts of shell, lime from burned shell, and sand (Honkerkamp & Devan, 4). Over time, the tabby hardens to become almost like stone in terms of durability and vitality (Honkerkamp & Devan, 4). Swarbeck took great pride in the buildings which were built on his property. He rationalized the high cost of tabby as being a wise investment in the long ride for its durability (Honkerkamp & Devan, 5). It was also around this time that Swarbeck had a large plantation home and many outbuildings built (Honkerkamp & Devan, 5). The labor used to construct the tabby slave cabins on th property is attributed to the slaves themselves (Honkerkamp & Devan, 5).  

 

             Below is a slide show sampling what Chocolate Plantation looks like present today (2018).

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             Swarbeck would sell the plantation in 1827 to a Dr. Charles W. Rogers (Honkerkamp & Devan, 5). At this point, Rogers added a two-story tabby barn and livestock to the plantation (Honkerkamp & Devan, 5). Rogers owned a total of 93 slaves in 1837 (Honkerkamp & Devan, 5). Thomas Spalding purchased 7,000 acres from Rogers and went on to gift a major section of the land to his son, Randolph, as a wedding present (Honkerkamp & Devan, 5). Randolph and his family resided in the plantation house until it was destroyed by a major fire in 1853, at which point they move to Roger's home on the Southend (Honkerkamp & Devan, 5). Roger's ran the plantation until 1857 when he moved to the mainland (Honkerkamp & Devan, 5). 

               The Civil War caused great upheaval at Chocolate Plantation. Many slaves fled for safety elsewhere while the plantation was looted (Honkerkamp & Devan, 5). It sat vacant for some time before the family of Jacob Green moved there (Honkerkamp & Devan, 5). The Green family produced modest crops of cotton which they sold in Savannah (Honkerkamp & Devan, 5). In 1912 the land was purchased by industrialist Howard E. Coffin to serve as a hunting retreat (Honkerkamp & Devan, 5). The family restored several structures including the barn and a slave cabin (Honkerkamp & Devan, 5). They also utilized the grounds as a plantation and maintained it to a degree (Honkerkamp & Devan, 5).  The Great Depression saw the land used as a private hunting retreat by R.J. Reynolds (Honkerkamp & Devan, 6). Today the majority of the island is managed by the Georgia Department of Natural Resources (DNR) (Honkerkamp & Devan, 6). 

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Laser Scanning Technologies

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                     The world of preservation has benefited from various methods of three-dimensional laser scanning which are used to recreate entire sites digitally. The technology works by capturing points in a point cloud. These points are a representation of a three-dimensional space. Multiple scans are unorganized until they are registered. Registration can be done automatically or manually in JRC Reconstructor. It will almost always need to be done manually because it rarely works when it is done automatically. 

   Using Scanners in Historic Preservation

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Document architecture

Research tool

Document objects

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        The following is based on notes taken in Professor Chad Keller's Class, Digital Innovations in                   Preservation.

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        Faro Focus Scanner

•  Non-invasive technology 

•  Great for use in un-safe buildings

•  Safe to use on museum objects

•  Used in combination with structure from motion to achieve accurate results

•  Point cloud data is registered to create a three-dimensional model 

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       Types of Scanners

• Time of Flight (TOF)- 

  • Emitting a pulse

  • Range coordinates are determined by calculating the differences between wavelength when it was sent and wavelength when it returns rather than time

  • This is good for long distances and is often used by departments of roadways for highway construction

• Phase Based-

  • Emits a continuous laser signal calculating differences between wavelengths​ when they were sent and when they return instead of calculating the time

  • This method is used on buildings and larger objects

  • This is the most commonly used type of scanning in the historic preservation field and is the method which we used on Chocolate Plantation (Faro Focus Scanner)

•  Optical Triangulation-

  • A laser and camera are used in unison to calculate​ the distance of an object

  • High resolution

  • Often used on smaller objects

  • Has a limited range

  • Is highly accurate 

•   Structured Light Scanner-

  • Combination of light projection source and camera to determine 3-D point values​

  • Light patterns with distortions

  • Limited range

  • Works best in low light conditions

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         Determine the project scope to chose the correct scanner

•    Size of the project

•    How much detail

•    Material composition of the object

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            Limitations

•     Shiny or reflective surfaces will reflect light back

•     Dark surfaces absorb light

•     Translucent surfaces allow light to pass through

•     Transparent materials such as skin, marble, wax can create subsurface scattering

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A toaster would not be a good candidate for

 laser scanning because it has highly reflective surfaces

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GIS & Arc Map

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                       GIS stands for Geographic Information System. This technology allows the user to import various layers of data into a map which provides the user with an interactive experience. 

For example, the City of Savannah has created a fun map which allows the user to tour various locally designated historic districts. Be sure to play with the interactive map to see if a buildings are contributing and when they were built. To take this fun tour, click the link below!

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  A screenshot of the "slider" feature in the Savannah Tour. This feature juxtaposes historic and current photographs to give insight into changes which have occurred over time. Example above: 223 East Gwinnett Street. Harden House, Circa 1892. 

 

 

 

 

 

 

                     For Sapelo Island, we utilized an image from an article on Chocolate Plantation and a satellite image from Google Earth. We took a screen shot of the image that we wanted to overlay on the satellite view of Sapelo. It is important to remember at the beginning that none of these files are Geo-referenced. Geo-referencing is the process of connecting geographic coordinates to a digital image so that multiple corresponding layers of data images can be connected. For Sapelo coordinate information, we began by seeking GIS information from McIntosh County (the county which Sapelo Island is located in). They did not have much information available so we had to get creative and look elsewhere. Brunswick happened to have useful GIS information that we could utilize for Sapelo. One of the maps showed Georgia Counties which contained an overview of Sapelo. This map provides the anchor coordinate system which will be used to plot and connect everything. The coordinate system in our selected map was from 1987.  

                        Once we had the coordinate system for our base map selected, we were then able to import our Sapelo overlay layer. The imported layer showed up directly on top of the base map, however it was not correctly aligned. First I lowered the opacity of the imported layer simply so that I could see the base map. I then had to select four points (a,b,c, & d) to properly layer both maps in their corresponding locations. Once both maps were combined, we then outlined all of the buildings on Sapelo. The great thing about this tool is the ability to enter data which is accessible in the map. Data we entered included the names of the buildings, date of construction, condition, date scanned, and material. 

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