The Krupps Stahlshütze (steel protector) is a Prussian automaton used to protect the Imperial Calculating Engines and other important facilities. Where most other nations built automata that can adapt to the terrain on which they are used, for this important job the Prussians have takem the unusual step of adapting the "terrain" to the automata. Sites on which they are used are levelled and surfaced to a high standard, and in buildings ramps replace stairs. This allows the use of a wheeled design with very little ground clearance, the wheels being covered by armour plating, with an aluminium chassis to minimise weight. Electric motors reduce noise. Generally considered to be successful, although they are slow to react and vulnerable to attacks which damage the "terrain" or push them over; they cannot right themselves. An unusual feature is the telescopic eye, which is moved in and out on bellows and improves the accuracy of its marksmanship. The down-side of this invention is that it has a restricted field of view and is easily attacked from the side, although sites where it is used are generally designed to limit opportunities for such attacks.
At least a hundred are believed to be in service. The photograph depicts a model generously donated to the Science Museum by the Kaiser; the unit designation and Prussian crest indicate that the machine it depicts is attached to the Imperial Archives. German soldiers generally refer to these machines as Pfeffertopfsoldaten, literally "pepper-pot soldiers".
(names suggested by Steve Dempsey, to whom many thanks - apologies to everyone who suggested names I didn't use)
(Is it more properly Krupp or Krupps when discussing the arms manufacturer?)
Later: modified image with a more realistic "hand".