28 
Transactions of the Society. 
To sum up the advantages and disadvantages of both models. 
The advantages in the Zentmayer form seem to me to he rigidity of 
limb and legs, and the body taking the Society's thread ; while that of 
the Jubilee is the firmness and size of the stage, and the possession of 
a substage condenser. The disadvantages of the Zentmeyer are the 
insufficient distance between the optic axis and limb, and the want of 
a suhstage condenser ; while those of the Jubilee are the weakness of 
the bar, the separation of the body in packing, and its not having the 
Society’s screw. 
In this summary I do not wish to make any invidious comparisons 
between Zentmayer’s and my own model, but merely to point out 
their respective advantages and defects, so that any future designer 
of a portable Microscope may avoid the errors of both designs. 
