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 microscope, 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 preferable, since it offers a more suitable surface to grasp in transferring from box or shelf to the desk, and vice versa.
Fig. 7.—Compound Microscope of Robert Hooke