4.3 Years 1910-1919

Number of slide rules: 37.

Variations in scale arrangements continued. See, for example, Dietzgen’s 1759-B with its R scale. Metal slide rules made their entrance in the U.S. during this decade as well. The Reitz scale arrangement was developed in Germany, which included K and L scales on the front with trig scales on the back of the slide. The K&E duplex models that include log-log scales for advanced calculations begin to gain popularity during this decade.

Some notable technical developments: air conditioning invented; World War I; nucleus of atom discovered.

Year	Maker	Model
c.1910	K&E	4041
1910	Richardson	Direct Reading Slide Rule
1910	Richardson	Direct Reading Slide Rule
1910-1912	Dietzgen	1761-AL
1910-1912	Dietzgen	1765
1910-1914	K&E	4053-2
1910-1914	K&E	4053-3
1910-1921	Dietzgen	1760-B
1911	Richardson	Direct Reading Pocket
c.1912	Richardson	Direct Reading (812)
c.1912	Richardson	Pantocrat 812
c.1912	Richardson	1776
c.1912	Richardson	Direct Reading Pocket
c.1912	Richardson	Direct Reading Pocket
1912	Richardson	Direct Reading Pocket
1912	Richardson	Direct Reading Pocket
1913	Dennert & Pape	No. 9
1913	K&E	4092
1913-1914	Faber-Castell	378
1913-1914	K&E	4133
1913-1915	K&E	4100
c.1915	K&E	4058
1915	K&E	4071
1915-1922	K&E	4045
c.1916	K&E	4058
c.1916	K&E	4083
1916-1920	K&E	4088-2
1916-1922	K&E	4088-3
1916-1925	K&E	4058 (student)
1917-1918	Richardson	Model of 1917
c.1918	Halden	Calculex
1919	Gilson	Midget
1919	K&E	4041
1919	KHH	Pocket Rule
1919-1927	Dietzgen	1759-B
1919-1927	Dietzgen	1759-B
1919-1927	Dietzgen	1759-B