328 LEEUWENHOEK AND HIS “‘ LITTLE ANIMALS” 
representation of ‘“‘a Leeuwenhoek microscope ’"—embodying 
all the features common to the extant examples. I have 
tried to show the mechanism as simply as possible and with 
the fewest and most easily comprehensible drawings, because 
I find all previous accounts incomplete, inaccurate, or difficult 
to understand. Several describers, indeed, do not themselves 
appear to have grasped the mechanism—either literally or 
metaphorically. My drawings are based primarily on the 
microscopes formerly in the possession of Mr P. A. Haaxman 
(The Hague), whose daughter—Mejuffrouw S. A. E. Haaxman— 
very kindly permitted me (on 29 June 1923) to take one of 
these priceless little instruments to pieces, sketch the various 
parts, and reassemble it. For the accuracy of my description 
I rely chiefly upon the notes and tracings which I made on 
this occasion. Unfortunately I have had no opportunity of 
testing any of Leeuwenhoek’s lenses. 
All Leeuwenhoek’s microscopes had an appearance like 
that shown in Plate XXXI, fig. 1. Properly speaking, they 
were not “microscopes” at all, but—as he himself usually 
called them—simple “ magnifying-glasses”. Hach consisted 
of a single biconvex lens (not a system of lenses); and the 
mechanical parts were contrived not to focus this lens upon 
an object lying on a fixed stage (as in a modern compound 
microscope), but in order to bring a movable object into the 
focus of the glass, which was itself fixed. It is important to 
realize this fundamental point in the design, which is highly 
original. It should also be emphasized that all these instru- 
ments were very small—even smaller than my drawings. 
They were generally made of the same metal throughout, 
though different metals were used (brass, copper, silver, and 
even gold occasionally): and the workmanship and finish 
were none too good. Leeuwenhoek concentrated his attention 
upon the optical part of his “microscopes” : and when he had 
succeeded in grinding and polishing and mounting a good lens, 
he evidently did not think it worth while to spend a lot of 
time in finishing off its mechanical accessories, which were 
made just.good enough for his purpose. 
Fig. 1 (Plate XX XI) shows the whole instrument from the 
back, as fitted up ready for use. Figs. 2 and 3 illustrate details ; 
and ‘fig. 4 is a diagrammatic longitudinal section. These 
drawings will, I hope, almost explain themselves— if carey 
studied ; but I may add the following notes : 
