2.2 The lifting of the grave
The main reason why Holwerda chose to lift and preserve the grave en bloc can be found in the description of the bones by Hanedoes, who describes them as grey with a soapy consistency. Holwerda literally argues (Holwerda 1908, 5-6) that further excavation of the skeletons in the field would make any preservation impossible and would hinder an adequate and detailed analysis of the bones. This is why he decided to have the area where the bodies were deposited covered in plaster and moved as a block to Leiden. He reasoned that in case of a failure to preserve the bones in this manner, the plaster would at least allow him to make an adequate cast (Nieuwenhuis 1908, 19). In order to do so the grave had been isolated by removing the surrounding sand to a depth of about 30 cm. The resulting block was subsequently covered in a thick cap of plaster, reinforced with iron rods and angle-pieces (ibid.) and several wooden boards were inserted under it. The pretty voluminous and heavy block in its wooden crate was then moved by horse and cart to the station and transported by train to Leiden.
The plaster cap was turned upside down in Leiden and the bones were cleaned under better conditions. It should be noted that, because of this, we are looking at the underside of the grave and as such have a mirrored view compared to the field situation. The work was carried out and supervised by Dr A. W. Nieuwenhuis, a well-known anthropologist. His report (Nieuwenhuis 1908) follows the initial report on the excavation.
Nieuwenhuis reports that he and several others were invited by Holwerda to further excavate the burials. Nieuwenhuis established that the grave had been lifted in its entirety, whilst removing the sandy and slightly gravelly subsoil. To carefully isolate and preserve the vulnerable bones they used little wooden sticks and brushes made of badger hairs. Loose sediment was removed with a vacuum cleaner. Nieuwenhuis also describes how the soil colour in the vicinity of the burial changed to a reddish colour, while the sediment surrounding the bones was more like a solid black mass. The bones themselves were in a very poor condition, which is why they were eventually consolidated with glue. After excavation and consolidation the burial was on view in the Dutch exhibition of the RMO for many years (NN 1930, 17-18).
While in later years several more attempts were made to lift other burials en bloc (Holwerda 1910, 4), it is probable that the one at Niersen was the first ever Dutch case. In any case it allows us to re-examine and reinterpret the find.