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Science & Mathematics

The Museum's collections hold thousands of objects related to chemistry, biology, physics, astronomy, and other sciences. Instruments range from early American telescopes to lasers. Rare glassware and other artifacts from the laboratory of Joseph Priestley, the discoverer of oxygen, are among the scientific treasures here. A Gilbert chemistry set of about 1937 and other objects testify to the pleasures of amateur science. Artifacts also help illuminate the social and political history of biology and the roles of women and minorities in science.

The mathematics collection holds artifacts from slide rules and flash cards to code-breaking equipment. More than 1,000 models demonstrate some of the problems and principles of mathematics, and 80 abstract paintings by illustrator and cartoonist Crockett Johnson show his visual interpretations of mathematical theorems.

"Science & Mathematics - Overview" showing 2182 items.

Page 101 of 219

## Model of a Rectangle or Oblong, Ross Surface Form #2

- Description
- This is the third in a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. The model is a 6 inch by 4 inch rectangle, divided into 24 one inch by one inch squares. A paper label attached to the model reads: Oblong 4x6.

- Comparing its area to that of a 6 inch by 1 inch rectangle (1985.0112.191), Ross noted that the area was four times 6 square inches, or 24 square inches. He generalized to argue that the area of a rectangle equaled the number of square units corresponding to the product of the length times the breadth.

- Compare models 1985.0112.190 through 1985.0112.202. For further information about Ross models, including references, see 1985.0112.191.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.191

- accession number
- 1985.0112

- catalog number
- 1985.0112.191

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Model of a Rectangle Bisected into Two Right Triangles, Ross Surface Form #8

- Description
- This is the eighth in a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. The unpainted rectangular wooden model is bisected along a diagonal. A paper label pasted to the model reads: Oblong 4x6 Bisected. According to Ross, this model demonstrates that a right-angled triangle with unequal sides adjacent to the right angle has half the area of a rectangle.

- Compare models 1985.0112.190 through 1985.0112.202. For further information about Ross models, including references, see 1985.0112.191.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.192

- accession number
- 1985.0112

- catalog number
- 1985.0112.192

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Model of a Dissected Trapezoid, Ross Surface Form #6

- Description
- This is the sixth in a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. The unpainted rectangular wooden model is cut into two pieces at one corner. It may be arranged so that the pieces form either a rectangle or a trapezoid. A paper label attached to the model reads: Dissected Trapezoid 5x7.

- Ross argued that the area of the trapezoid equaled half the sum of its parallel sides, multiplied by its breadth.

- Compare models 1985.0112.190 through 1985.0112.202. For further information about Ross models, including references, see 1985.0112.191.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.193

- accession number
- 1985.0112

- catalog number
- 1985.0112.193

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Dissected Polygon, Probably a Ross Surface Form

- Description
- This unpainted wooden model consists of two doweled pieces that can be arranged as a quadrilateral. The model is incomplete. It resembles other Ross surface forms.

- Compare models 1985.0112.190 through 1985.0112.202, especially 1985.0112.193. For further information about Ross models, including references, see 1985.0112.191.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.194

- accession number
- 1985.0112

- catalog number
- 1985.0112.194

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Rectangle Transformable Into an Obtuse Triangle, Probably a Ross Surface Form

- Description
- This is apparently is one in a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. The three doweled pieces of this unpainted wooden model can be arranged either as a rectangle or as an obtuse-angled triangle.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.195

- accession number
- 1985.0112

- catalog number
- 1985.0112.195

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Dissected Rhomboid, Ross Surface Form #5 (incomplete)

- Description
- This is the fifth in a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. The unpainted wooden model is divided into two pieces, with the smaller piece missing.

- With the smaller piece, the model could be arranged either as a parallelogram or a rectangle. A paper label attached to the model reads: Dissected Rhomboid 4x6.

- Ross argued that the parallelogram (or, in his terminology, rhomboid), like the rectangle, was the product of its length and its altitude.

- Compare models 1985.0112.190 through 1985.0112.202.

- For further information about Ross models, including references, see 1985.0112.191.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.196

- accession number
- 1985.0112

- catalog number
- 1985.0112.196

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Dissection of a Parallelogram into Triangles, Ross Surface Form #9

- Description
- This is the ninth in a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. The unpainted wooden parallelogram (rhomboid in Ross’s terminology) is bisected along a diagonal into two scalene triangles. A paper label attached to the model reads: Rhomboid A 4x6 Bisected. According to Ross, the model shows that if a rhomboid (parallelogram) is cut diagonally through the opposite acute angles, two equal obtuse-angled triangles result.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.197

- catalog number
- 1985.0112.197

- accession number
- 1985.0112

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Dissection of a Parallelogram into Triangles, Ross Surface Form #10

- Description
- This is the tenth in a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. The unpainted wooden rhomboid (parallelogram) is bisected along a diagonal into two scalene triangles. Two adjacent sides on the left are equal, as are two adjacent sides on the right. A paper label attached to the model reads: Rhomboid B 4x6 Bisected. According to Ross, the model shows that if a rhomboid is cut diagonally through the obtuse angles, two equal scalene triangles result.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.198

- catalog number
- 1985.0112.198

- accession number
- 1985.0112

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Trapezium or Quadrilateral, Ross Surface Form

- Description
- This is one of a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. This example, what Ross called a “trapezium,” is a quadrilateral with four unequal sides, none of them parallel. A diagonal groove joining two opposite vertices, dividing the quadrilateral into two triangles. Ross recommended finding the area of these triangles from the length of their sides.

- A paper sticker attached to the model reads: Trapezium. Another sticker reads: SCALENE TRIANGLE. A second mark on this sticker reads: It is the only operation for which the Ross Blocks have no objective proof or illustration, such objective proof is probably impossible.

- This model is not listed in Ross’s 1891 manual. Here he had written: “The trapezium is measured by dividing it up into triangles. This disposes of all the quadrilaterals.” He apparently revised this view.

- If none of the angles of an arbitrary convex quadrilateral is known, knowing the length of the sides does not suffice to determine the area of the figure.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.199

- catalog number
- 1985.0112.199

- accession number
- 1985.0112

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Dissected Square, Ross Surface Form #11

- Description
- This is the eleventh in a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. The unpainted wooden square is bisected along one diagonal, with wooden dowels to hold the pieces together. Along the other diagonal, one of the triangles is bisected. On the back, an inscribed circle is indicated as well as the radius of the circle and a square inscribed inside it. A paper label glued to the object reads: SQUARE 6x6.

- This is the first in a series of models in which Ross considered the area of a regular polygon to be made up of isosceles triangles, with base equal to the length of the side of the polygon and height equal to the radius of the inscribed circle. Summing the area of the triangles, he found that the total area equaled half the perimeter of the polygon times the radius. In this case, each of the four triangles had base 6, height 3 (the radius of the inscribed circle), and area 9. The perimeter is 4x6 or 24, half the perimeter is 12, and the area is 36. This was the same area found by multiplying the length of the sides of the square.

- Although they are not listed in his 1891
*Manual*, Ross also would make models of regular polygons with 8 and with 16 sides, similarly divided into triangular sectors. Examples of these have catalog numbers 1985.0112.201 and 1985.0112.202. He then, like A. H. Kennedy before him, generalized the dissection to represent the area of a circle (see 1985.0112.203).

- For further information about Ross models, including references, see 1985.0112.191.

- Location
- Currently not on view

- date made
- ca 1895

- maker
- Ross, W. W.

- ID Number
- 1985.0112.200

- catalog number
- 1985.0112.200

- accession number
- 1985.0112

- Data Source
- National Museum of American History, Kenneth E. Behring Center

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