**Slide rules come in a wide variety, from short and simple to big and complicated.** Some are geared toward trigonometry, with an easy way to read sine/cosine tan/cotangent, logarithms. There are scales for square root and square, cube and cube root, division/multiplication. When you see the result on a slide rule, you can slide the viewer up and down the scale and immediately see proportions and ratios.

So, look around on ebay and pick up a classic by Pickett, Koeffell, Faber, Hemmi, or others. Keep it around, in a drawer or on display. Power out and your iPhone calculator on the fritz ? no problem. The really good ones hold their value well as a small investment.. condition, condition, condition is the rule. The more scales, and the older, the more valuable.

**And, don’t ignore the extremely useful circular slide rules, calculators.** They come in a large variety, usually plastic or thin metal, with several concentric rings of scales and a sliding pointer. For example, see Concise Circular rules. still being made. For many professionals in engineering, drafting, electronics, or even business math, these devices are still extremely useful, partly because of their speed. no need to punch buttons.

**SLIDE RULES.. are very cool.** Okay, so we have computers and iPhones.. BUT, we all must pay some honor to the fine precision devices that allowed engineers to invent the a-bomb, early electronic gadgets, and so much more that we totally depend on today. So, if you get the urge to insult them, or laugh at them, hold it in. They are built extremely well so they last a very long time. plus, if the power ever goes out… … and it does… you can grab a slide rule. OR a solar powered calculator, to crunch the numbers. Oh, well, I still like slide rules. they’re cool I have a few, maybe more than a few. They’re like tube radios… yeah, they’re old, but way cool. retro.

** But REALLY, there are some really good reasons to own a slide rule !**

** Easy to use, and FAST.** Slide rules may look complicated at first glance, but they are quite easy to use. Once you learn a few basic principles, you apply them to all the various scales on the rule. Slide rules have been made customized to various industries, or types of calculations done, such as pipe flow, electronics, etc, to enable fast calculations.

** SO, why a slide rule, when one can use a modern scientific calculator ? ** Well, for one thing, it’s very interesting to learn about how we all got our fantastic electronics gadgets. There are people living today who remember having almost no access to a calculator. At that time cash registers and adding machines had hundreds of moving parts, very heavy, and were used only in industry and government. Indeed, some types of calculators were kept hidden. It was a military or business secret advantage. Back then you had to learn your numbers in school and know how to do mental calculations, and paper and pencil, to do math. Once slide rules were invented, it enabled a tremendous boost in math productivity over many decades, because more people could make precise calculations. That’s extremely important in engineering and business. A slide rule was like Lotus 1,2,3, the first spreadsheets, in the effect it had. So, slide rules enabled us to have all the modern gizmos that need tons of math. They enabled engineers to design electronic circuits much faster, leading to our modern computers.

** To most people, using a slide rule seems weird.** It’s just a different way of looking at calculating. Remember, the abacus was used for a very long time, because it worked, plain and simple. Slide rules are like that. A simple system, used repetitively. Once you learn it, it’s easy. A lot of people need to use basic math during daily activities. Perhaps you need to calculate square feet, or know how many inches in 50 centimeters. Or maybe calculate gas mileage. Beyond that, many professionals need to determine rations quickly, such as artists, engineers, draftsman, and so on. For specific tasks, a slide rule is very effective and fast. Plus, they are cool. Never need batteries.

**Advantages of a slide rule. All math is just a combination of four basic relationships. add / multiply and subtract / divide Multiplying is just a lot of adding at once, and dividing is a bunch of subtracting. When calculating moving systems, like speed, motion, direction and for 3 dimensions such as volume, one often needs to determine roots…squares, cubes. This can be done easily on a slide rule. **

** Using the ‘slip-stick’ to great advantage.** The slide in a slide rule can position numbers in relation to another number, and you get the result on the vertical line. One advantage of this system is in determining factors and ratios, since you can slide the vertical indicator back and forth and look for common factors and ratios. With an electronic calculator, you may have to reenter a bunch of numbers, trying to get close to the result you are looking for. On a slide rule you can move the slide back and forth to come to a quick conclusion, such as for estimating square feet, or cubic meters, etc.

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**Do YOU know how to navigate ? **

**Without navigation, civilization could not exist.**

**You need to know where you are and where you want to go.**

**Then you can use some of these tools to help you get there.**

**Oh, and don’t forget to take along a map when you travel.**

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**Honda made a huge number of very reliable small motorbikes and scooters since the 1960’s.**

These days getting around can be expensive, and many of our trips are to someplace nearby… an appointment, pick up the mail, do a little shopping, etc. If you get yourself a nice, single cylinder on / off road bike, it will save you a lot of money, and you’ll also have a lot of fun. Once you own one, you’ll never be without at least some transportation. They are cheap to maintain and insure, too.

Check out these bike models from Honda. Passport C70, Cub, CT70, CT90, CT110, CT 125, CL series, the ST90, XL80, XL100, and many others. They last a long time if reasonably cared for. I own one from 1980 that has barely 1000 miles on it. runs and looks great.

Look for them on Ebay and Craigs List. States vary with licensing laws, so do a little research. To go on the road you need headlights, mirror, and at usually signal lights.

In many countries scooters and small motorcycles are far more common than cars. They make total economic sense. You’d be shocked to see what some people carry on them, or how many people.

Suzuki, Kawasaki, and Yamaha also have made great small motorcycles and scooters. I recommend the earlier ones from 1960’s through 80’s. you can often find one in great condition, stored in a garage or barn. they can last for literally decades, so you can pass them down through the family.

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**They make very high quality stuff, with ingenious designs.**

**There are many times when you need a small screwdriver, knife, scissors, light. **

** Swiss+Tech makes a whole line of really handy gadgets. Great for travel, hiking, camping. **

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