CHAPTER II 
COMPOUND MICROSCOPES 
The compound microscope has undergone wonderful changes 
since 1667, the days of Robert Hooke. When we consider the 
crude construction and the limitations of Robert Hooke’s micro- 
scope, we marvel at the structural perfection and the unlimited 
possibilities of the modern instrument. The advancement made 
in most sciences has followed the gradual perfection of this 
instrument. 
The illustration of Robert Hooke’s microscope (Fig. 7) will 
convey to the mind more eloquently than words the crudeness 
of the early microscopes, especially when it is compared with 
the present-day microscopes. 
STRUCTURE OF THE COMPOUND MICROSCOPE 
The parts of the compound microscope (Fig. 8) may be 
grouped into—first, the mechanical, and, secondly, into the 
optical parts. 
THE MECHANICAL PARTS 
1. The foot is the basal part, the part which supports all 
the other mechanical and optical parts. The foot should be 
heavy enough to balance the other parts when they are inclined. 
Most modern instruments have a three-parted or tripod- 
shaped base. 
2. The pillar is the vertical part of the microscope attached 
to the base. The pillar is joined to the limb by a hinged joint. 
The hinges make it possible to incline the microscope at any 
angle, thus lowering its height. In this way, short, medium, 
and tall persons can use the microscope with facility. The 
part of the pillar above the hinge is called the limb. The limb 
may be either straight or curved. The curved form is pref- 
erable, since it offers a more suitable surface to grasp in trans- 
ferring from box or shelf to the desk, and vice versa. 
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