Xll PREFATORY NOTICE. 



data can bear. At page 60, it is stated that the 

 hand that is, the muscular feeling, can divide 

 space to greater nicety than the eye; and as that 

 is not in accordance with the common belief, I 

 shall here state my authority. Mr. James Gardner, 

 of Regent Street, the geographer, can rule, blind- 

 folded or in the dark, with the natural angle of a 

 diamond on hard white metal, fifty-one lines in 

 the fiftieth part of an inch, and cross them at the 

 same distances, with an additional line each way 

 to complete the number of squares. There are 

 thus 2550 spaces, or 2551 lines in the inch in 

 length, and there are 6,502,500 squares between 

 the lines in the inch. These too are more regular 

 in their sizes than the majority of people could 

 draw lines by the eye at, say, the fortieth or even 

 the twentieth of an inch. Small as that tactual, 

 or rather muscular division is, the limit of it is in 

 the instruments and not in the feeling ; for if it 

 were possible to obtain any cutting substance suf- 

 ficiently fine, there seems no reason why each of 

 those little spaces should not be equally divided 

 into any number of parts; so that, if the eye 

 could see the work after it is done, it is probable 

 that the muscular feeling could discriminate down 

 to the primary atom. 



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