The Museum of HP Calculators
The K&E slide rule shown below used its extra length to display extra accuracy. The Picket was simply a standard rule blown up for advertising and instruction.
Picture of a K&E 4053-5 20" rule. (~107K)
Closeup on the K&E 20" rule (~40K)
Picture of a Picket 4 foot slide rule. (~43K) The HP-25 is shown to indicate scale.
Some straight rules were more complicated and had two or three slides. Some, like the one shown below were four-sided and had four slides. This rule was used in the computation of excise taxes and dates to around 1800-1830. This rule was made out of boxwood with brass inserts and had a satisfying heft and quality feel.
Picture of a four sided Dring & Fage excise rule. (~58K)
End view of the four sided rule. (~10K)
Sectors were somewhat similar to slide rules but were designed for working with angles and trigonometry. They pivoted rather than slid. The sector shown below was made out of ivory with a brass hinge. Like the four-sided rule above, this sector had brass inserts at heavy use points.
Picture of a Sector. (~114K)