t 69 3 
the Office Protractor. The limb c d of the bevel is 
made to be taken a part at h by drawing c h out of 
a brass socket fastened to h d, for the purpose of 
packing it in the box. On each side of e d scales 
of equal parts may be made^ 
In order to keep the bevel in its position against 
the edge of the protractor a small button i k is 
made to project on it from the groove and to be turn¬ 
ed down in the direction i 1 to lie below the move- 
able limb when folded down^ 
This instrument, although not quite so expedi¬ 
tious in its operation as the Office Protractor^ is yet 
so vastly superior to the common protractor, that' 
surveyors who have had it in use have considered 
it such an essential part of their equipment for the 
woods, that no consideration could have induced 
them to be without it. 
A Letter from Robert R. Livingston, Esq. 
President of the Society, and Minister Plenipo^ 
tentiary of the United States in France, Ben¬ 
jamin De Witt, M> B, of Albany, 
ON THE USE OF PYRITES AS A MANURE. 
Paris, 10tb October, 1802. 
Dear Sir, 
T 
A HAVE it not yet in my power to reduce to any 
order the few observations I have been able to make 
