Mapping the Past
One of the first things a surveyor learns when studying surveying is how ancient Egypt was perhaps one of the earliest civilizations to use surveying--in much the same way we use it today. The "rope stretchers," as surveyors were referred to in ancient times, laid out, oriented and leveled structures, one of the most famous being the Great Pyramid of Khufu built around 2700 B.C. These early surveyors also enabled tax collectors to assess property more accurately by preserving and re-establishing property lines lost to the annual inundation of the Nile River.
Today, the practice of surveying is teamed with Egyptology as well as archaeology on the Giza Plateau. One of many joint efforts is the Cairo-Brown University Expedition, a venture of Brown University in Providence, R.I., and Cairo University in Cairo, Egypt. This expedition is recording reliefs and inscriptions as well as mapping the tombs in the Abu Bakr cemetery located in the northwest corner of the Giza Plateau within the Western Field, about half a mile west of the Great Pyramid.
Headed by Egyptologists Dr. Tohfa Handoussa of Cairo University and Dr. Edward Brovarski of Brown University, the expedition has worked for four seasons from 1999 to 2004. A season typically lasts five weeks from late December to early February. The team has included an archaeological site supervisor, archaeological draftsman, professional engineer, chief epigrapher, photographer, students from both universities, and for the last three seasons a registered professional land surveyor, Jay Gilliland.
Gilliland, a transportation surveyor party chief with District 3 of the California Department of Transportation (CalTrans) in Marysville, Calif., began surveying in the U.S. Army in 1967. He gained further experience surveying in Egypt by working on the Greater Cairo Wastewater Project, a USAID (U.S. Aid for International Development) joint venture. Five years after working on the project, Gilliland's project director contacted him about Dr. Brovarski's need for a surveyor on the Cairo-Brown University Expedition. Once preliminaries were resolved, Gilliland took a temporary leave of absence from his position with CalTrans. He met Dr. Brovarski in Cairo in December 2000.
Mapping MastabasThe Cairo-Brown Expedition's study covers a 10-acre site within the Western Field, a cemetery that remained in use from about 2606 to 2250 B.C. Though the pyramids were constructed as burial sites for Egyptian kings, the Western Field was laid out for family members, nobles of the court and others--possibly artisans or craftsmen who had performed special favors for the Pharaoh. The individual tombs are referred to as mastabas, the Arabic word for bench.
Mastabas are rectangular tomb structures with walls that taper in as they go up, making the top a slightly smaller footprint than the base. Mastabas vary in size, probably due to the political status, wealth or position of the owner, but sometimes made to simply fit the available space. More detail becomes visible as centuries of sand are layered away with each expedition.
On top of the mastabas are the openings of the burial shafts. The shafts are about 5 ft square and up to 30 ft deep, many times going down to the bedrock. Most of the time, mastabas were constructed alone with false doors on the east-facing sides where family members prayed for the deceased. At the base of some false doors, offering basins have been found where friends and family could leave liquid offerings of water or beer for the deceased in the afterlife. Occasionally, small chapels decorated with beautiful reliefs and hieroglyphs can be found attached to the mastabas.
Over time, some mastabas were built on top of or used portions of others. As a result, some parts of the Abu Bakr cemetery are an intricate three-dimensional maze of overlapping, intertwined tomb complexes. The Cairo-Brown Expedition brought Gilliland to Egypt to map the tombs and help solve this puzzle. The maps resulting from his survey work, like epigraphy (see explanation of epigraphy below) depict what is there now--without interpretation--before wind and time steal these artifacts from us.
Melding Yesteryear and TodayEgyptologists and archaeologists have used surveying to help them document their sites for a long time. Only in recent years have they applied modern surveying hardware and software. A few archaeological sites Gilliland visited in Egypt had staked out a grid and laid out string lines along the grid. Then as artifacts were uncovered, the archaeologists could locate their finds relative to this grid. This method, while functional, was hard to duplicate and difficult to integrate into adjacent projects.
For the Cairo-Brown Expedition, Gilliland brought his laptop and an HP 48GX calculator with Tripod Data Systems (TDS, Corvallis, Ore.) Survey Pro software. In 2003 and 2004, he also brought a TDS Recon handheld data collector equipped with Survey Pro.
David Goodman, RPLS, PE, a retired CalTrans surveyor, performed the hard work of setting monuments and establishing horizontal and vertical control on the Giza Plateau in previous seasons. He kindly shared his data with the Cairo-Brown Expedition, giving them a great jump-start on the project.
On the site, Gilliland collected the survey data while another volunteer, his friend and former employer Jim Langford, PE, a civil engineer from Western Colorado, served as his rodman. Langford roved the cemetery--scaling crumbling walls, skirting shafts 30 ft deep, identifying worthy targets for mapping, and at times providing a feeding frenzy for the sand fleas at the bottom of the burial shafts. Every evening after Gilliland cleaned up the data, he transferred it to Langford. In turn, Langford imported it into Autodesk's (San Rafael, Calif.) AutoCAD 2004 program. Then he added grids, title blocks and annotations to prepare maps for the field archaeologists to use the next day.
The mastabas were initially mapped without any excavation completed. These first plots helped Drs. Handoussa and Brovarski choose areas for the labor-intensive removal of the sand. A team of about 25 pick men and basket men carefully exposed new surfaces and removed the sand. Once the foundations of the mastabas were fully uncovered, Gilliland and Langford mapped the new finds. At the end of the day, Gilliland transfered the new data from the Recon into TDS ForeSight computer-aided surveying software on his laptop. After a few simple edits, the file was updated and the obsolete lines were removed. Gilliland then generated a new drawing file for Langford, and each night he prepared revised maps.
Unearthing Equipment and Software AdvantagesWhile a CalTrans project might use more than 200 codes with four attributes per code, Gilliland only needed about 20 codes in the Egyptian project. Gilliland used an option in Survey Pro that creates a numbered text file such as 1: Limestone Block, 2: Wall, 3: Top, etc. Inputting these numbers linked by the symbol "&" (i.e., 1&2&3) creates a full description of each shot. Gilliland created color-coding for the line work with separate colors for limestone block, rubble and mud brick.
Although Gilliland was familiar with the software program from his previous work in Egypt, the Cairo-Brown Expedition project was the first time he had used it on the Recon data collector. Admittedly, the Active Sync software that transfers the files from the data collector to the laptop locked up once; and although a 10-hour time difference exists, instructions received from Craig Ayers-Hale of TDS technical support via phone and E-mail had Gilliland running everything smoothly in a short time. After using the keyboard on his HP 48 for so many years, Gilliland was concerned about adjusting to the Recon's on-screen keypad. He found it wasn't hard, "just different."
Gilliland said the 2004 expedition's weather was "pretty blustery," with the team working through a few cold, windy, rainy days. During the 2004 expedition, the team experienced a couple sandstorms, but the equipment held up better than the guy running it. The Recon stood the test of the environmental conditions, and it remained protected against water and dust. "I didn't get any sand in it at all," Gilliland says. Gilliland also didn't have to worry about the serial and USB ports and the Compact Flash slots of the Recon since they all are O-ring sealed.
These surveying and archaeological efforts have melded to create a more precise and complete database of the Western Field area than previously possible. This digital database is an ongoing mosaic of the mapping process that can be merged with other mapping being done on the Giza Plateau. Dr. Brovarski said Gilliland's and Langford's work gave the Cairo-Brown Expedition much greater detail and accuracy, and also helped the team to accomplish more work in less time.
"The impressive technology Jay and Jim used at the Abu Bakr cemetery has produced an amazingly detailed map of the site," Brovarski says. "The new maps show how imprecise the earlier plans produced by more conventional mapping methods were.
"From the excavator's perspective, it is extraordinarily helpful to have architectural plans and details surveyed the day before, then plotted on the large map of the cemetery the next morning. With the older methods, we had to endure long waits before the final product might be seen. What's more, the daily updates of the mapping allow the excavator to immediately evaluate the progress of the work and to plan the next days work with confidence. And because the system is digital, we're also able to plot the tombs to any scale or size, which is a great aid to interpretation."