MULDBJERG DWELLING PLACE—TROELS-SMITH 581 
zontal measures are correct according to the scale of the drawing. 
Next, all the vertical measures are leveled out. In this way it is 
possible later to give a correct picture of the peat wall and the layers 
in it based upon the drawings and the levels (pl. 1). 
Ficure 3 (left)—Ash (Fraxinus excelsior L.). 
Ficure 4 (right)—Wych elm (Ulmus glabra Huds.). (Drawings by A. Noll S¢rensen.) 
The next task is to characterize the various layers that have been 
distinguished. Most of the layers consist of a mixture of different 
components. Fen peat, for instance, often contains the following 
elements: Roots and rootlets of herbaceous plants (7Z'urfa herbacea) ; 
fragments of stems and leaves of herbaceous plants (Detritus her- 
bosus) ; minor parts of alder twigs (Detritus lignosus) ; and finally 
mud or, as it is also called, gyttja (Limus detrituosus). Just as a 
chemical compound may be characterized by a simple formula giving 
the proportions of the atoms in the molecule, it is also possible to 
characterize a deposit by the proportions of the components contained 
in the layer. For the sake of later considerations regarding the 
genesis of the layer, it is important to know exactly how the deposit 
is built up and the components of which it consists. 
The excavation of artifacts, the determination of deposits, and 
the characterization of the composition of the various deposits should 
finally result in drawings both in plane and section showing the layers 
provided with deposit symbols that indicate the elements of which 
the layers are composed. Together with the photographs, the draw- 
