L The List
clocksWe would have only a vague idea of what time it was without clocks. You can kind of guess what time it is by looking at shadows and positions of the sun and moon, but our fast paced modern life requires more accurate measurements than that. Besides the obvious examples of wall clocks and watches (itself a relatively recent invention), you'd be amazed at what else in your life has clocks in it. These include: your TV, computer, cell phone, microwave, electric stove, stoplights, etc.
This is another of those inventions that occurred in so many places at roughly the same time and so long ago that we aren't sure who first invented them, but the clock as we now know it didn't gain widespread use until after the 1500's. Even then, they were not in the private possession of the "common man" until after the Industrial Revolution.
computational devicesBy "computational Devices" I mean anything that can automatically carry out mathematical formulas without step-by-step guidance from a human user. This rules out devices of ancient origin such as number systems, tally sticks and the abacus since those devices are merely tools to keep the human mathematician from losing his/her place. I am talking about devices that do all the work for you once you ask the device a math-based question in some form. This can be anything as simple as hitting the "3" "+" and "4" buttons on a calculator to something as complex as typing in the variables into a computer program that then calculates the flight path of the Space Shuttle.
We've become quite dependent on our computational gadgets such as calculators, computers, automatic timers, sensors in our cars etc. that many people would be hard pressed to do even basic math problems in their head.
corrective lensesAnyone who has trouble seeing clearly has come to rely on corrective lenses of some kind. Whether they are modern-day versions of the eyeglasses that Benjamin Franklin perfected (much debate still exists as to who invented the very first eyeglasses), or whether they are the nearly invisible contact lenses, a huge percentage of people in industrialized countries wouldn't even think of leaving their home without these marvels. Most users of glasses come to think of them as extensions of their bodies and are rather shocked and alarmed when the device gets broken or their eyes become too weak for their current prescription.
electricityFor the modern person living in an industrialized society, going a few hours without electricity is a scary thought. If the power goes out, we're on the phone to the electric company almost immediately, asking when it will be back on. We rely on it to see in the dark, to keep warm when its cold and cool when it's hot. Some people would die very quickly without it (such as premies in incubators and people with pacemakers). Most people use electricity or at least benefit indirectly from some product of it 24 hours a day.
Yet it is quite true that there was a time when people did not know how to harness the power of electron flow. It has long been held that Benjamin Franklin was the first to truly harness electricity. However, some historians argue that even the ancients knew about electricity (citing the "Baghdad Battery" as an example). Still it is clear that large scale dependence on electricity for daily life didn't begin until after Franklin.
gluePeople have been using glues of one form or another for thousands of years, so it's hard to say who invented it first. These early glues were made from sticky natural substances like tree sap and the excretions of certain animals. However, the glue that you and I first think of when we hear the word was patented by a company in England in 1750. This glue was made partially from fish paste but was superior to that made from tree sap. The glue you and I use on a regular basis was invented by Ashworth Stull in 1942. The formula was sold to Borden and became known as the still famous "Elmer's Glue".
Let's face it, if its not held together by a fastener of some kind (see entry #9 above), its held together by glue. Did you know that most of the shoes you wear are held together almost entirely by glues? The list of things for which glue is used is very long but it includes: toys, cars, computers, particleboard and plywood (your house probably wouldn't exist without it), furniture etc. etc.
One of the most amazing glues: "Krazy Glue" was invented by Hary Coover in the 1940's. Like many inventions, it was created almost by accident. The main ingredient, cyanoacrylate, was first intended as an ingredient for a new plastic needed for rifle sights in WWII. When it was discovered that the stuff stuck to everything "like crazy" at room temperature, it was used for a glue instead.
horseless carriagesAn outgrowth of the invention of the wheel, this device was still considered a "plaything of the rich" as late as the 1890's. The first horseless carriages were steam-powered and the first among them was built as a toy for the Chinese Emperor by a Jesuit priest named Ferdinand Verbiest around 1672.
It wasn't until Henry Ford perfected the mass production line in the early 1900's, that a car began to become affordable to the middle class. Cars did not fully eclipse the use of the horse for transportation until after World War I. In fact, during WWI, some soldiers actually rode into combat on horseback.