Thursday, August 15, 2013

Continuing work at the William Kaulehelehe House Site


 The Queen Anne's Lace is still blooming in the area around the William Kaulehelehe House site and we are still finishing up excavations there, although most of the activity has been at the Little Prouxl site.  I spent a bit of time last week doing some finishing up work to close out the small 1 X 5 meter trench that tested the Hawaiian preachers house (Block K).  I had expected to find a few subsurface post and stake holes like we often encounter in the area beneath the dirt floors of the fur trade houses at Fort Vancouver.  After carefully troweling the floor and finding a few minor stains that had little depth and may have been associated with natural processes, I decided that the western-most unit needed at least one more level to make sure that we had not missed anything.  As often happens, this decision led to an increasingly more complex excavation challenge and some very interesting finds.  The eastern margin of the unit contained a nice gray clay, similar to the house floor at the Little Prouxl site, although this was on the outer, western edge of a shallow pit feature that we had excavated earlier in the summer.  Importantly, this clay seemed to dive to the east.  Following this clay proved to be very surprising as what had been thought to be culturally-sterile sediments below the floor turned out to be a fill with a similar color and texture, but that contained a number of artifacts from the house construction including square nails and window glass.

Gilt ring found at the William Kaulehelehe house site.
Interestingly, on the western margins of the clay-lined pit or trench, a man's gilt ring was found. While not of much real value (the gilt is all but gone), this ring is somewhat more fancy than the typical trade rings found at the Fort.  While far from a priceless piece of jewelry, it is intriguing to think that this may have been the personal property of the Hawaiian minister that was lost one day.  One wonders if it had any meaning to him or if he even mourned its loss.

The clay dipped further east into the hole requiring some time to clear.  Surprisingly, a small ceramic sherd was found that has very
rounded edges.  While the transferprint pattern is quite distinctive, the rounding and the small size of the object suggest that it may be an artifact that was subjected to a unique formation process after it was deposited.  Another site associated with the Catholic Mission that we dug on City of Vancouver property about 9 years ago contained similar objects that we interpreted to be gastroliths, or gizzard stones, probably from chickens or some other domesticated fowl.  Birds don't have teeth and to compensate for this, they injest small rocks and other objects (sometimes glass and sometimes ceramics) to help in grinding down their food.  These gizzard stones have been found on archaeological sites before and give a clue, albeit diminutive in size, as to the presence and sometimes the processing of fowl.  

Gastrolith found at the
William Kaulehelehe House Site

On a related note, the clay beneath the ring appears to contain a great deal of bird shot although it is unknown if this represents an area where birds were processed or simply the loss of many very small objects.  In a small test of the clay, I found nearly 50 pieces of shot.

As we had some cloud cover today, I spent a bit of time cleaning up the features of Block K including the newly exposed clay-lined pit/trench and then took photographs to create a 3D model of the test trench.  I made a short YouTube video that you may access at the link below.
YouTube video of 3D Model of Block K
 

Monday, August 12, 2013

Working with the Oregon Archaeological Society

Oregon Archaeological Society Volunteers help out at the Little Proulx site. Staff Elaine
Dorset and Katie Wynia are training the volunteers on the first day.
 Well, the field school is now over and we have begun the next phase of excavations with the Oregon Archaeological Society.  This is a less frenetic pace, as the lecture series is now over, the work at the Spruce Mill is completed and we have volunteers out on Wed, Friday and Saturday. On Tuesdays and Thursdays, we catch up on paperwork and finish work that the volunteers have left us.  We have been working at the Little Proulx site with the volunteers and are completing the removal of the clay-lined house floor.  There is a significant concentration of artifacts in the eastern part of the house and appear to have encountered the western edge of the house floor in units pictured above. Surprisingly we have not yet encountered the hearth.
Key and hardware found at
 the Little Prouxl House Site.

We found a very interesting cupreous fragment that may be part of the lock for a large key found in the adjacent unit.  The size and characteristics of the key appear to match that of a very large door key. This may match the time period when a U.S. Army Surgeon, Levi Holden, occupied the house (early 1850s). The Army rented some of the buildings from the Hudson's Bay Company, including the Little Prouxl house.  Additional information on Holden is listed in an article that was prepared by one of our volunteers last year, Jason Ainsley: http://www.nps.gov/fova/parknews/upload/NCRI-Report_8-2FINALDRAFT.pdf

Royal Coat of Arms of the United Kingdom, found at
the William Kaulehelehe house site.


We are also finishing up work at the William Kaulehelehe house site.  A feature that lines up with the hearth may be a footing feature, which also incidentally lines up nicely with the southern wall of our reconstructed House 1 (the Engage' house).  We appear to be on the north wall of the structure.  On excavation of the area immediately west of this feature, a bit of clay house floor was identified and a curious set of metal fragments.  These appear to be part of a tin (perhaps a tea tin) or the lid to a can or jar.  At first they appeared to have an Irish theme, with a harp and possibly a clover, but on closer examination we have discerned it is the royal coat of arms of the United Kingdom.  As noted by Meagan Huff from the Fort Vancouver Facebook page, "The top fragment is half of a crown, the second from the top contains part of the phrase "Honi soit qui mal y pense," the motto of the Order of the Garter. The fragment third from the top has two barely-visible lions, which represent England. The bottom fragment has a harp, representing Ireland. The banner below it would have contained the words "Dieu et mon droit," the motto of the English monarchs. Research into what this object was for will be ongoing although its presence at a Hawaiian minister's house is quite intriguing with its statement on colonialism and identity with the British empire.

The change in pace has also given me the opportunity to work more closely with the digital forms and iPads to directly explore their use in the field.  A couple of thoughts after a week.  I found the same issues with the glare from the iPads that the students did, particularly when holding them level over the excavation units to attempt to get a plan view of a level or feature.  Even with the brightness increased to maximum, it was difficult at times to get a view of the unit and snap the picture and not lose part of the unit in the image.  This usually required a few shots to get the images I wanted.  Not a huge issue but an aggravation.  The nice thing is that the camera is available at any time for photographing, so I am taking many more images than I would normally.

Another benefit is the ability to use photos to help draw shapes.  Last week I was unhappy with the way in which a mule shoe had been drawn on the house floor by one of the students.  In order to get a better drawing, I took an image of the artifact in-situ, imported it into my level form, then scaled it to the correct size and location, zoomed in and traced the edges of the artifact.  This was done much more accurately and quickly than the hand-drawn method.  I have since tried this method with unit level rocks and the edges of surfaces/floors to improve the quality of the drawings.  I think this has been done to good benefit.  Once the image is traced, the photo is deleted leaving only the line drawing work.

I have been working on some fairly complex levels, with a variety of objects, sampling locations and artifact recording.  The forms seem to take a lot of time, probably longer than a paper form in the field.  The good thing is it is the result is quite legible (a chronic problem for some researchers and students) and the data can be extracted out of the form.  I think I like the annotation  capabilities the best. 

In reviewing the notes from the field school, I have seen that some of the students were quite unhappy with the iDraw program for drawing profiles, and felt they could draw the profiles much faster using paper and pencil (in fact some of them did).  While this may be a factor of unfamiliarity with the program and use of a tablet computer as much as frustration with the speed of entry, there are likely some valid thoughts.  I will explore the use of iDraw to annotate some of these student profiles this week and will report back on its use later.  Regardless, the longest time expended in the field, however, is still the bagging and recording of artifacts, particularly when there are a lot of artifact bags (a typical problem of historical archaeological sites). I will need to think about a means to improve the speed of this process with tablet computers.


Tuesday, July 30, 2013

Surveying the Spruce Mill Site

Over the past weeks, teams of students have been learning archaeological survey skills at the site of the World War I Spruce Mill, a significant home-front site associated with the processing of old growth Sitka Spruce cut from the forests of the Coast Range of Oregon and Washington and the Olympic Peninsula. 
Besides learning basic pedestrian survey techniques, the crews have also conducted subsurface surveys searching for remnants of the old cut-up mill building, the shops, and tent city for the 3,000 troops that manned the mill. An excellent history of the site by Ward Tonsfeldt helped to guide probing along with remote sensing work by Kendal McDonald reported in an earlier post.
Students excavated probes at locations defined by the magnetometer anomalies recorded earlier in the summer and at locations discovered during monitoring of the removal of some hangars a few years ago. The results confirm that there is abundant evidence of the WWI facility including concrete foundations, concentrations of wire nails and railroad spikes, and even an axe head. Notably, we have been able to see some of the vegetation anomalies associated with the Spruce Mill appearing more distinctive as the ground dries up.

Dry grass in more closely cropped areas suggest where Spruce Mill foundations sit. The ones inside the fort denote where the loading docks to the East and South of the main mill building were located.

The foundations of the sawdust burner are clearly visible as linear dry grass areas adjacent to the reconstructed bake house. 


House Floors, Imaging, and Modelling with Tablet Computers

Over the past two weeks, we have exposed the house floors in both the Little Proulx House and the 1 X 5 m test trench in the WilliamKaulehelehe House.  In both cases, the floors contained evidence of burning consistent with the destruction of both houses by the US Army ca. 1860.  The floors are rich with Hudson’s Bay Company-era artifacts, including beads, buttons, ceramics, vessel glass, window glass, square nails and many other items. There is a very distinctive burnt surface in the eastern half of the Kaulehelehe House site with some evidence of north-south running wooden planks which may indicate a wooden floor that burnt in place or a fallen wall.  In the midst of this rich deposit of artifacts and charred wood and charcoal, a door pintle was found.  This object is of particular importance as it is reported that the U.S. Army removed the windows and door from the Kaulehelehe House prior to torching it on March 20, 1860.  This door pintle and the associated burn layer adjacent to it may be a direct link to the destruction of the house site and the eviction of the Native Hawaiian preacher.
The William Kaulehelehe House site showing the hearth and some preserved planks and charcoal staining.  A door pintle is located in the northern portion of the image.  A water screen sample was previously removed from the southwest corner of the unit and the floor around the hearth has already been excavated.
We had two groups who came to tour the site from the Ke Kukui Foundation.  It was amazing to share these finds with people who have such an interest in Hawaiian heritage and the story of the Hawaiian diaspora.

Dr. Bob Cromwell and I interpret to the Ke Kukui Foundation tour at the Little Prouxl House Site. 

Following the E'se'get Archaeology Project, I decided to capture the hearth using the Autodesk 123D Capture program with my iphone.  As we do not have a 4G connection or wireless access in the field for the iPads, I did not use the tablets for this experiment.  I was quite surprised at the resolution and ease with which 3-D models could be generated in the field.  I took 36 photos of the feature from different angles and submitted them to the Autodesk server that crunched the data in about 15 minutes.  The results were later converted into a video animation on my lap top that I have posted on my University YouTube channel:

YouTube animation of the William Kaulehelehe House Site Hearth (Feature 406)
 As we use the tablet computers, we have begun to discuss improvements to field recording that are facilitated by the concentration of many tools associated with one device.  An obvious improvement would be to take a photograph of the floor of each level as a background for drawing things like rocks, sediment variation, feature boundaries, etc.  Without tablet computers, this is difficult as there are generally only a few cameras on each project.  As each tablet contains a high-resolution camera, it is much easier to collect photographic data on the floor plans (and profiles).  Both the iDraw and pdf Expert apps can import images, although the iDraw app is more sophisticated.  

One issue has been with correcting the distortion caused by cameras that were not placed directly above the floor.  The use of photo-processing apps that remove the distortion (orthorectify the photo) and create a planimetric view may allow a resolution to this problem.  There are a variety of apps available that straighten and flatten images, including programs designed to capture the text and images from whiteboards.  We will be experimenting with some of these apps to improve the capturing of these data.  Simplifying the drawing process may help to streamline the archaeological recovery of data and allow for more sophisticated data to be collected and processed directly in the field. 

Once the distortion is removed, then the picture can be cropped to the size of the unit floor (usually 1 x 1 m) and then dropped into and registered to the image space on the recording form.  Annotations can be placed on top of the image.  For those annotations that were placed prior to the completion of the plan, a translucent image can be generated that will show the earlier details underneath the image.  Theoretically this will free up time drawing things like rocks that are obvious in images, while leaving the ability to annotate those aspects of the floor plan that are not as easy to discriminate with photography.

Tuesday, July 16, 2013

More on Battery Life

After a week of use, a few statistics can be developed regarding the average use of the iPad and its battery capacity during archaeological excavation.  Table 1 below identifies my tracking of the battery life used each day for the ten iPads. iPads 5, 9 and 10 were only used for the cemetery survey work which only occurred on Thursday and Friday last week.  In addition, Friday afternoon (7/12) was truncated by a lecture and the water screening demonstration so only represent about a 5-hour day.  Due to a glitch, iPads 1 and 2 were not charged the night of 7/9/2013 and the students started 50x50-cm shovel tests (with traditional paper forms) the morning of 7/10/2013 while the units were charging.  iPad 4 was at 8% at 1 pm on 7/10/2013 when it was recharged, therefore only representing about a 4.5 hour work day.

TABLE 1. iPad BATTERY LIFE USED OVER A FIVE-DAY FIELD TEST IN JULY

  7/9/2013 7/10/2013
iPad# Start End Battery Life Used Start End Battery Life Used
1 78 42 36 100 45 55
2 68 3 65 100 84 16
3 100 86 14 86 75 11
4 100 61 39 61 8 53
5 100 100 0 100 100 0
6 81 56 25 100 55 45
7 76 55 21 100 100 0
8 100 59 41 100 67 33
9 100 100 0 100 100 0
10 100 100 0 100 100 0
7/11/2013 7/12/2013
iPad# Start End Battery Life Used Start End Battery Life Used
1 100 73 27 100 97 3
2 100 50 50 100 79 21
3 100 93 7 100 100 0
4 100 42 58 100 82 18
5 99 24 75 100 37 63
6 100 60 40 100 88 12
7 100 37 63 100 50 50
8 100 68 32 100 48 52
9 100 14 86 100 41 59
10 99 22 77 100 38 62
7/13/2013
iPad# Start End Battery Life Used
1 100 60 40
2 100 79 21
3 100 99 1
4 100 98 2
5 100 100 0
6 100 40 60
7 100 2 98
8 100 19 81
9 100 100 0
10 100 100 0      

As shown in the Table, the cemetery monument recording work, which generates many more forms and digital images, uses up a lot more battery life.  For the two days in which they recorded cemetery headstones, the student's iPads used between 59% and 86% of battery life.  Because Friday was only a five-hour day, and Thursday was a training day when the new crews were getting oriented to the recording strategy, the average battery use might be a bit more for a fully trained crew over an 8 hour workday.  The average for Thursday of 79.3% is probably conservative.  

Ignoring the partial days and charging glitches, the other seven iPads measurements over the five days is 35 observations of battery use.  The average use was 34.0% of the battery with a standard deviation of 24.26.  There was a significant range between no use (the iPad was not used) and 98% of battery use. As iPads are tied to particular excavation units, no use indicates that those units were not excavated that day.  Excavation tasks included filling out the four-page level form, taking images, and some intensive use of iDraw to map the World War I railroad grade. I think a fully trained professional field crew (excavating at a rate of 2 10-cm levels per person per day) will likely generate more forms and perhaps use more battery life depending on the complexity of the site.   Even so, there appears to be plenty of capacity for excavation forms and digital images. This is consistent with the results from other projects, such as the Pyla-Koutsopetria Archaeological Project on Cyprus and the E'se'get Archaeology Project in Nova Scotia.

Monday, July 15, 2013

House Floors, the Spruce Mill, and Other Excavation Notes

Concentration of beads being discovered at the Little Prouxl House Site.

Hearth exposed below house floor
(about 70 cm top to bottom -- west is up)
Over the past two weeks we have been exploring the house floor of the Little Proulx House Site and clearing more units to expand on these excavations.  There have been a number of notable finds, including a cluster of about 70 white beads (what appear to be small, hot-tumbled tube beads) in the southwest corner of one of the excavation units.  The location of this cluster is mapped using the annotation tool on the PDF Expert program. Just to the west of this, a concentration of baked clay (or "bisque" as it is used in the Pacific Northwest, probably from the house fire when it burned), a charred beam, and concentrations of  bisque and charcoal likely associated with the destruction of the house.  In one area nearby, a nicely-defined hearth with a charcoal-black rim and reddish-brown interior was discovered below the clay floor.  This may be a hearth that preceded the construction of the house or an earlier iteration of the structure before the clay floor was
laid down.



We are also shovel probing the Spruce Mill Area, exploring some of the magnetic anomalies identified by Kendal McDonald a few weeks ago.  The probes are about 40 cm in diameter and are dug to at least 50 cm in depth.  The first week of probing we found many interesting strata tied to fill associated with the World War I mill site and later uses of the property for aviation and other U.S. Army and City of Vancouver uses. We found surprisingly few metal objects or other sources that could be tied to the anomalies.  This past week we used a metal detector to really home in on the magnetic sources and were rewarded with many metal objects, including cast spikes, a likely aviation fuel line, and other objects.
Excavation of a shovel probe at the Spruce Mill cut-up mill site.
Pearson Air Museum, including the repurposed World War I hanger  in the background.
Back at the dig site, we used iDraw to map the top of one of the World War I Spruce Mill spur lines that rest above the Little Prouxl House Site.  Besides being an excellent training excercise, we are troubleshooting the use of iDraw for illustration of plan and profile maps.

Monday, July 8, 2013

Battery Life in the Field


One of the concerns raised by some with the use of tablets in the field was battery life and if the tablets would last through an entire day of field recording. I am happy to report that battery usage during excavation is about 20-40% during the day depending on the number of forms worked on. While the school is digging more slowly than a professional crew in the field, it appears that there is plenty of juice to record excavation data without having a supplemental source or having to swap out units.

In contrast, the cemetery recording project uses up an entire battery each day. One tablet ran out of juice before the final photos of monuments were recorded. This is undoubtedly due to the much larger number of forms created each day during cemetery recording.

By recording battery life each day, we should be able to get some metrics on the number of forms generated contrasted with battery expenditure. This week I will collect some data.