Inner Ring
On the inner ring, "MPH" (mile per hour) refers to "speed in-
dex". This index is used to calculate the speed involving any
data per hour. On the inner ring, "STAT" (statute miles) and
"NAUT" (nautical miles) are for conversion of distance units.
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The following examples serve as a guide of how to use
the slide rule.
SPEED CALCULATION:
What speed is required to go 10 nautical miles in
15 minutes?
OUTER RING
Known Factors: Distance: 10 nautical miles Time:
INNER RING
15 minutes
• Align "10" arrow on the outer ring with "15" on the
• The speed required can be found directly above the
The answer: 40 nautical miles per hour
Time Calculation: How long will it take to go 10 nauti-
cal miles at a speed of 40 miles per hour?
inner ring.
"MPH" marking on the inner ring.
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