PHYSICAL SCIENCE. 1013 



4019e. Arithmetical boxes, made by the St. Petersburg 

 School Workshop. 



4019f. Zito witch's arithmetical box. 



4020. Paulson's abacus for integers. 



4O20b. Kanaeff's abacus for integers and fractions. 



4020c. Model of Ilyin's abacus. 



B. GEOMETRY. 



4O28a. Collection of 6 geometrical forms. Made by the 



St. Petersburg School Workshop. 



4O28b. StrookofPs collection of 7 geometrical forms. 



4029a. Collection of 16 geometrical forms prepared by 

 the inmates of a Russian prison, 



4Q33a. Cube of three. 



4033b. Cube of a binomial quantity. 



4:033c. Square of attrinomial quantity. 



Cube of a trinomial quantity. 



Two-plane angle made of cork. 



The Pythagorean theorem. 



Four-sided geometrical figures. 



Six Polygons. 



Boldt's geometrical apparatus. 



Zitowich's apparatus for determining the cubic content of 

 geometrical bodies. 



Ogerovsky's geometrical puzzle. 



"'' .- " ' 

 Ogerovsky's trigonometrical diagram. 



C. GEOMETRICAL DRAWING. 



Shildknecht's apparatus for demonstrating the theory of 

 projections. 



StrookofPs collection of school apparatus for geometrical 

 drawing. 



