Home      End       Spreadsheets METHODS OF CALCULATING THE CAPACITY OF POTTERY VESSELS - PotSize

When dealing with pottery assemblages the capacity of the vessels is an important factor. Woodward (1997)
“Vessel volume is obviously as important as shape, if not more so, in the consideration of function” Page 216 Barrett (2000).

When searching the literature to find out how to measure vessel capacity we only found a limited number of references. Appendix 1,Barrett C (1980). P 155 Woodward (1997)
Even the reference found did not give much detail of how to measure capacity, in fact some references (not mentioned here) we could not understand.

The work described here arose out of a reassessment of pottery found in the New Bodlian site in Oxford. Wheeler C (2005)

This work discusses different methods of measuring vessel capacity and gives details of how to use these methods and discuses some problem and sources of errors. Suggestions are given to make the methods easier to use. Also a set of spreadsheets (in Excel) is provided to carry out the calculations used in these methods.


There are various methods of finding the capacity of a vessel.

1. Where a complete vessel is available it can be filled with sand or a similar material and the volume of the material measured. However in general we are not dealing with complete vessels. Also would any curators allow you to fill their precious vessels with sand? This should be the most accurate method as we are measuring the capacity directly.
   
   
2. Another method is to treat the vessel as a pile of circular slices and then calculate the volume of each of these slices treating each as a truncated cone, as there is a formula to calculate the volume of a truncated cone. The smaller the height of these slices the more accurate the calculation although this means that more measurements are needed. This can be a rather longwinded process. Also it needs a detailed knowledge of the profile of the vessel and measurements. This detail is not always available.
   More details of Method 2
   
   
3. It would be possible to consider the vessel as being made up of various regular figures (there is a formula to calculate the volume of most regular figures). This method would have to be adjusted for each shape of vessel and again is rather longwinded unless the shape is simplified.
   More details of Method 3
   
   
4. In many pottery assemblages there is only a limited number of vessel shapes although these occur in many sizes. It might be possible to devise a formula for each of these shapes that only depends on measurements that are generally recorded for pottery vessels i.e. rim, girth, and base, and height. This will not be concidered in any more detail as the details would depend on the particular vessel shapes.
   

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