USD $159
M.H. Mear Gas Flow Calculator Circular Rule (new/mint)
Stock: 1
USD $59
Coast Navigation Simex Course Converter (new/mint)
Stock: 1
USD $119
Stephenson-Pfahl Hardenability Slide Rule
Stock: 1
USD $85
Fearns W25 Castings and Forging Weight Calculator Circular Rule (new/mint)
Stock: 1
USD $85
Fearns-Mear Machining Time Calculator Circular Rule (new/mint)
Stock: 2
USD $159
M.H. Mears Pipe Flow Calculator for Liquids & Gases (new/mint)
Stock: 1
USD $59
Do you need to measure fallout radiation from a nuclear detonation? This is what you need to do that! I’m sure there are other ways, but this way will absolutely not fail you (doesn’t need batteries), so long as you are sufficiently far away to safely be able to operate the rule.
Stock: 3
USD $275
5.5″ Circular Aviation Slide Rule
Constructed with one rotating film disk, and rotating cursor on each side. A very sophisticated and beautiful flight computer for doing altitude, pressure, wind drift, time, temperature, and fuel problems.
The rule gives simultaneous solutions in both metric and US/Imperial units, without being cluttered or hard to interpret, an outstanding mechanical and artistic design. Still in demand today among many pilots, but very hard to find.
Made of ‘Aristopal’, comes complete with zippered leather pouch. We have had many requests for this rule from all over the world, this are the first 618’s we have ever had available for sale, all in excellent condition. The similar 617 has an additional rotating wind arrow on the back face, not present on these models. The earlier 616 does not have the red reciprocal degrees printed on the rear compass rose, or the wind arrow.
(22 scales on front, Wind scales on rear)
Stock: 1
USD $95
Fearns A8 Metric Weight Converter, includes case and manual, one side converts imperial to metric, and the other metric to imperial.
Stock: 1
USD $165
5.5″ Circular Aviation Slide Rule
Constructed with one rotating film disk, and rotating cursor on each side. A very sophisticated and beautiful flight computer for doing altitude, pressure, time, temperature, and fuel problems.
The rule give simultaneous solutions in both metric and US/Imperial units, without being cluttered or hard to interpret, an outstanding mechanical and artistic design. Still in demand today among many pilots, but very hard to find.
Made of ‘Aristopal’, comes complete with zippered leather pouch.
Stock: 1
USD $225
This special late production Foxboro flow rule is used to calculate flow parameters and rates for liquids, steam or gas. This is the version custom made for Foxboro by Hemmi of Japan, and has red, blue and black engraved and filled scales.
Pipe schedules are color coded for easy operation. The unusual design uses many dedicated scales sets on both sides, and includes the fitted factory box and manual, and gold embossed leather case, all in MINT condition!. It’s a rule you will really enjoy in your collection, or on the job doing steam or hydraulic pipe fitting.
Stock: 1
USD $25
A double sided slide chart used for frequency calculations. Includes original instruction sheet in German.
Stock: 1
USD $25
This star finder and identifier is more versatile than many others, as it comes with 10 different latitude overlays ensuring this star-finder is useable in many different areas.
Includes manual, 10 latitude overlays, double-sided circular map/chart, and protractor.
Stock: 1
USD $25
Made from two durable acrylic discs with one half having a star map, and the other having the field of view and time of day, this star finder is easy to use and very popular.
Stock: 1
USD $35
Clear and easy to use, this star finder has two concentric rings on one side for lining up the chart to your surroundings, and easy to understand directions on the reverse side.
Stock: 2
USD $150
Don’t be caught in the cockpit without this device! Set comes complete with case, manual, multiple charts, and double sided circular slide rule.
Provides arithmetic and vector solutions for for aircraft speeds of 90 to 2 000 knots, with consideration of errors due to aircraft acceleration. Dead reckoning capability of a plotting board.
Stock: 1
USD $15
If you’re still refusing to use the metric system, and don’t want to do your calculations using fractional lengths of football fields, then this circular slide chart will be very useful. On the inner ring it provides calcualtions in both fractional and decimal quantities.
Stock: 1
USD $35
This ruler uses temperature responsive liquid crystals to read-out room temperature in C/F. It also features metric and imperial measures on the upper and lower edges, and a slide in the center for completing metric/imperial conversions for mass, volume, and distance.
Stock: 1
USD $15
The Sterling “Add-It” machine uses an included stylus to allow a user to add and subtract. Usage directions printed on the front of the device.
Stock: 1
Sphere Research Corporation