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AN IMPROVED METHOD FOR REGULATING THE THICKNESS OF 
MICROTOME SECTIONS. 
F. M. Anprews, Indiana University. 
In some of the Minot forms of microtomes several springs and other parts 
are arranged in such a manner as to cause the specimen in the machine 
to be set out the desired distance for sectioning. The above mentioned 
arrangement is usually very complicated, and apparently unnecessarily so, 
in many machines of this type. This adds greatly to the expense, liability 
to get out of order, and makes the apparatus unduly large and heavy. A 
microtome, as most other types of machines, should not be made heavy 
simply to remain in one position, but should only be heavy or substantial 
enough to prevent springing or getting out of allignment when in use. Of 
course this is a point that merits due consideration in a microtome when 
such yery thin sections are to be cut, but still the present weight of most 
such machines of the microtome type can be greatly reduced without 
detriment. A simple table clamp is all that is necessary to obviate most 
of the difficulty of shifting of the position of the machine. The chief 
weight is, of course, in the framework of the machine especially in the 
wheel base, slide pillar and uprights of the microtome I used. This is 
true of most machines of this type. The weight of these parts could be 
reduced to one-third or even one-half of what it is without sacrificing any 
necessary rigidity. The weight of the wheel and frame running on the 
slide pillar could be much reduced especially by the proper adjustment of 
the balancing of the weight of the two since they are connected to the same 
shaft. This same balancing of weight is seen in the adjustment of the 
pitman rod on the crank of engines and other much more delicate machin- 
ery. The difference in weights and balancing here referred to in the case 
of microtomes is so considerable as often to cause considerable inconyen- 
ience and unsteadiness in operating the machine. Part of this adjust- 
ment, as the machine I used as now arranged, could be partly arranged for 
by a different length in the threading of the main shaft so as to throw the 
heavy parts of the machine, concerned in the motion, more nearly in bal- 
ance when the microtome is in operation. A machine which is arranged for 
cutting sections in the ways here described, should be so arranged and ad- 
justed as to turn or start with equal ease in any position. Its construction 
should also be such that it could be stopped instantly and at any point 
without haying to turn a special device at the top of the slide pillar. That 
a microtome is not a machine that is expected to be moved about much, 
has no bearing on the question for whether it is moved much or little an 
unnecessary amount of material and weight is often present in many of 
its parts which could from the standpoint of cost and convenience often 
be eliminated. The question of setting the block for cutting thin sections 
is arranged in a very accurate and better way on the Jung Sliding Micro- 
tome by means of an incline plane and a spiral thread of definite value for 
each adjustment. Even in this machine the weight far exceeds what is nec- 
essary. The arrangements of springs on the microtome used by me were, 
as is generally the case sooner or later, a source of annoyance and often 
