Just having a look in the second "The Model Engineer and Amateur Electrician" Feb 1898, The construction of model Dynamos and Motors. over type, nominal out put8 V, 1Amp, speed 3500rpm. Important dimensions are given as figures, the others sizes can be taken at discretion. The field core should be the best cast iron. The armature core(D) is made from a number of stampings of best charcoal sheet iron about 1/32" thick. It is shown with either a two pole armature for a dynamo, or a three pole armature for a motor, it needs three poles to self start.
There are plans for 4 or 5 dynamos, or motors in the first year of ME & AE, one at least has laminated armature and stator.
Ian S C