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MINUTES OF PROCEEDINGS OF 
THE SECTOGRAPH. 
BY 
LIEUT. T. J. TRESIDDER, R.E. 
There is no doubt that irregular ground can only be properly repre¬ 
sented in miniature by a model made to scale. A map, even when 
closely contoured, is not by itself a sufficiently finished representation 
of country for all purposes—it must be supplemented by sections, for 
which the contours furnish the data. But even if a model were as 
easy to make, and as portable when made, as a map, it could not take 
the place of the latter; because its irregular surface would be unsuitable 
for drawing upon. 
Some means, then, of giving to a map the advantages of a model 
without its defects, appear to be wanted; and it is with the view of sup¬ 
plying this want that a scale has been designed—called the Sectograph— 
for use with contoured maps. 
In order to gain conciseness without sacrificing clearness, the des¬ 
cription of this scale is given in the form of answers to the three 
questions— 
What is it for ? 
What is it ? 
How is it used ? 
What is it for? 
1. If you have a contoured or numbered plan of any ground or 
work, and wish to make a section of it, it is to enable you to make 
that section with the least possible expenditure of time and labour. 
2. If, under the same circumstances, you wish to solve certain prob¬ 
lems regarding the plan, in the solution of which one or more sections 
would usually be necessary, it is to enable you to solve such problems 
without the trouble of drawing the sections. 
