In 1874 a logboat – a boat made by hollowing out a tree trunk – was discovered sticking out of the mud following a change in the course of the River Conon. It was later given to the then-named National Museum of Antiquities of Scotland, its donation being recorded at the meeting of the Society of Antiquaries of Scotland on 12 December 1881 (below), nestled between donations of a knocking stone (a bit like a large mortar, used for processing grain) and textiles associated with the discovery of a bog body.

The exact circumstances of its discovery and recovery are not described, but it was eventually donated to the museum by a local doctor, Dr William Bruce (1835-1920). Dr Bruce is credited with being the first doctor to describe polymyalgia rheumatica, a condition causing pain and stiffness in the muscles around the shoulders, neck and hips that was not formally recognised or named for another sixty years.

In July 2013, as a result of improvements made to the museum’s storage facilities, a group of three large, unidentified timbers became more accessible for inspection. They appeared to be joining portions of a single logboat. The discovery of the frayed remains of a paper label adhering to part of the gunwale confirmed the curators’ suspicions that the timbers were indeed parts of the ‘lost’ River Conon logboat. It now seems that at some point, the logboat was sawn into two main sections (one of which has subsequently split into two), possibly to facilitate storage in the cramped cellar space of the former NMAS in Queen Street, where they were virtually inaccessible for study.The donation of the boat to the museum was never formally registered and as a result the object does not appear in the museum’s printed catalogue of 1892; instead - and despite its size! - the whereabouts of the logboat was to become a long-standing mystery.

DATING THE LOGBOAT

Logboats were in use across the British Isles and beyond for thousands of years. There are over 150 recorded discoveries in Scotland, although only around thirty survive. It was previously thought that all logboats were prehistoric, but radiocarbon dating has shown that their use spans at least two millennia, from 500 BC to AD 1500.

Radiocarbon analysis of the River Conon logboat revealed that it dates to the 13th century AD, which fits well with the wider picture from Britain and Ireland, where the majority of logboat dates fall into the Medieval period and prehistoric examples still remain relatively rare.

The radiocarbon dating was supported by dendrochronological analysis (tree ring dating), which indicates that the River Conon logboat was probably fashioned in the late 13th/early 14th century AD. It was formed from a mature oak tree which was around 300 years old when felled.

This is the first logboat to be dated by dendrochronology in Scotland. It produced a 229 year sequence which has been dated to AD 1045-1273. The outermost ring of the measured sequence lies on the heartwood/sapwood boundary (the curved lower edge of the log in the photograph); the sapwood (the outermost growth rings of the tree) have decayed away over time. As the heartwood/sapwood boundary is present it is possible to estimate a felling range for the log by adding a sapwood estimate to the date of the outermost ring. The British sapwood estimate of 10-46 years is used in Scotland. Thus, the log was probably felled sometime between AD 1283 and AD 1319.

The innermost rings of the log could not be measured because they were too decayed but there were probably up to 40-50 rings before the first measured ring. Allowing for the missing inner and outer rings, a log of circa 300 years of age was used to make the logboat.

EXAMINING & REIMAGINING

Analysis of the logboat by expert Bob Mowat revealed that it was not particularly well-crafted. On well-made examples, small holes through the timber are used to allow the controlled removal of timber, to result in a uniform thickness around the vessel; the River Conon logboat has no thickness-guage holes and as such the bottom of the boat is very thick. This would have reduced the boat’s buoyancy as well as decreasing its carrying capacity.

Although now sawn into pieces, the logboat would have been around 5m long, which places it at the middle of the recorded range of sizes of Scottish examples. Notches on the top edges suggest that the boat may have been part of a paired logboat, where two vessels of a similar size are fastened together. Alternatively, it may have had an outrig. Either of these would have served to make a more stable vessel. However, no excavated examples of paired logboats are known in Scotland so this remains conjectural.

LASER SCANNING & RECONSTRUCTING

The logboat was laser scanned at 0.5mm resolution to create an accurate three-dimensional record, and to assist in the creation of images of how the boat may have looked. Several hundreds of millions of point measurements were collected, totalling over 3GB of data.

Find out more about logboats:

McGrail, S., 1998. Ancient Boats in North-West Europe: The Archaeology of Water Transport to AD 1500. London: Longman.

Mowat, R. J. C., 1996. The logboats of Scotland: with notes on related artefact types. Oxford: Oxbow Books.

Mowat, R. J. C., 1998. The logboat in Scotland. Archaeonautica 14.1 (1998), 29-39.

Strachan, D., 2010. Carpow in context: a late Bronze Age logboat from the Tay. Edinburgh: Society of Antiquaries of Scotland.

Sponsored by the Hunter Archaeological and Historical Trust.