In the very northeast of the Netherlands the province of Groningen lies , cramped between the Dutch province of Friesland and the German region East Friesland. The far east of Groningen was low and wet and though there is no written evidence it is generally agreed that here have been blacksmiths making the here shown model of ice skates. The pictures in detail 1a and 1b are from 1880 and seem to confirm this. 
 

Fig.1: Groningen speed skates, around 1880
Groningen ice skates are much alike Friesland ice skates but with a significant detail difference: the grain of the wood in Groningen skates follows the neck line (detail 1c). This implies that the wood must have had a heat treatment as to form it after the front shape of the runner blades. Friesland skates were sewed from planks and therefore the grain in Friesland skates is horizontally throughout the skates (detail 1d).

Manufacturer: unknown
Mark: none

Technical data: total length: 42 cm; height over ice: 2.8 cm; platforms: 29 cm long, 5.5 cm wide; runner blades: 11 mm tall, 3 mm thick; weight: 220 g
 

Fig.2: Groningen speed skates, around 1890

Manufacturer: unknown
Mark: none

Technical data:
total length: 44 cm; height over ice: 3.6 cm;
platforms: 30 cm long; 5.5 cm wide;
runner blades: 13 mm tall, 3 mm thick;
weight: 245 g including straps