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Slide Rule Cache Mystery Cache

Hidden : 11/27/2005
Difficulty:
4 out of 5
Terrain:
3.5 out of 5

Size: Size:   regular (regular)

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Geocache Description:

Puzzle cache requiring understanding of the operation of a slide rule

The posted coordinates are bogus; they mark the intersection of Post and Majors roads. Note that Post was a major manufaturer of slide rules before the advent of calculators.

The cache is located at N AA B0.CC W DD EE.FF

The latitude AA B0.CC is calculated using a straight slide rule which is 10” between the left and right ‘1’ index marks, with the C scale in the central slide and the D scale stationary (the stator). For each calculation the index marks are aligned at the start.

AA: The cursor is moved 5.3148 inches to the right of the leftmost mark on the D scale. Read AA from where the cursor intersects the D scale. If you do not obtain a value of 34, then your math calculations are not up the rest of the puzzle.

B: The slide is moved 3.0103 inches to the right. From the left index of the C scale, the cursor is moved right 6.9897 inches, and the value of B is read from the D scale.

CC: The slide is moved left 2.2185 inches; the cursor is placed over the value 2.5 on the C scale and the value is read from the D scale.

The longitude is computed using a circular slide rule with the C scale on the inner moveable wheel and the D scale on the stationary outer ring. Each calculation begins with the indexes and cursor aligned.

DD: The cursor is moved 5.8074 radians clockwise, and the value is read from the C scale. If you do not get DD=84, recheck your math.

EE: The interior wheel is rotated counter-clockwise 3.7829 radians. The cursor is rotated clockwise 2.9978 radians, and the value of EE is read from the C scale.

FF: The C scale is rotated clockwise 100.348 degrees. The cursor is moved over the 3 mark of the C scale and FF is read from the D scale.

This will remain a members-only cache until first found or 30 days, whichever comes first.

Parking is available .2 miles from the cache at a true bearing of 19 degrees. Do not park anywhere else.

Initial contents include both straight and circular slide rules, a $WG, and several kid-friendly items.

Access to the cache involves some scrambling and may involve mild bushwhacking or wading, depending on your approach.

Additional Hints (No hints available.)