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Transactions of the Society. 
scope is placed, may have his hands on the stage of the latter where 
the object is which he is examining, whilst he looks into the eye- 
piece to see what he is doing while dissecting this object; which 
amounts to saying that the proportions which have appeared to me 
most suitable are those where the stage is raised about a decimetre 
(4 in.) above the table, and the entire tube of the Microscope is only 
about 2 dm. (8 in.) long or a little more. The difficulty of arranging 
and suitably fixing the object which one examines being equally one 
of the greatest inconveniences in this kind of research, especially in 
the case of very small objects which a displacement of 1/10 mm. will 
cause to travel out of the field of the Microscope, and which one 
ordinarily thus loses without being able to find them again, this 
inconvenience requires that such objects should be capable of being 
turned on themselves in every direction without displacing them 
from their situation in order to attack them from all sides. This 
advantage I have obtained by simply making the stage of the 
Microscope movable on its centre. By this means, without touching 
the object itself, whether it be fixed or not, one can place it in all 
desired positions, and that without its receiving the slightest shock 
which might displace it. The observer requiring to have his hands 
firmly resting on this same stage while dissecting the object which 
he is studying, I have also found that the most suitable width for 
such a stage is that where it has about 1 dm. (4 in.) in breadth.” 
He goes on to state the requirements of such a Microscope in a 
similar way at some length, but enough has been quoted to suggest 
that we meet here for the first time with a precise definition of what 
have become the standard dimensions of the Continental Microscope 
stand. 
Up to 1835, which appears to have been about the date of the 
introduction of this model, there was no uniformity in the design 
of Microscope stands, and it appears to me that this pattern succeeded 
in ousting all others by conforming in some degree, as described 
above, to the proportions of the human body, much as a spectacle 
frame is adapted to the face. One may be sure that for continuous 
and laborious use, such as falls to the lot of a professional worker, such 
an instrument as is least productive of muscular fatigue will be most 
fruitful in results. For it is evident that a man sitting at a table in 
the attitude of work will have his eyes naturally situated about 14 in. 
above the table, and about 6 in. from its edge, so that his arms, as 
they rest on the table before him, will bring his hands close together 
in front, the direction of his eyes falling upon them without con- 
straint, at an angle of about 15° from the vertical. A stand which 
falls into place within these dimensions will save fatigue — an advan- 
tage for which much may be sacrificed in many kinds of work. With 
a weighted foot, if produced slightly backwards, sufficient stability 
may be gained for such a small degree of inclination, or the vertical 
position will not be found extremely irksome, at least to the pro- 
