I recently stumped Canada's wizard of wipers.

"I can locate wipers for vehicles going back into the 1920s," Roger Bayley confidently claimed from his office in Brantford, where he dispenses wiper wisdom as the product applications guy for Gates Rubber, Canadian distributor of Trico products.

We were chatting about these simple devices that constantly seek attention by waving back-and-forth in front of our eyes, but which are usually ignored until the rainy day we realize our vision is frighteningly reduced.

So how about a 1968 Morgan, I asked? It went quiet. I could hear the pages of reference books turning. But nothing turned up. Actually it was a bit of an unfair question. Britain's Morgan turns out less than 500 cars a year and so doesn't find space in many catalogues.

If I'd left the request with him, Bayley would have eventually found the answer; he doesn't miss often and this source of arcane wiper information has an advantage over any rivals: Trico is a giant that provides original equipment units for seven out of 10 vehicles built in North America.

The inventor of the wiper appears to be one Mary Anderson of Alabama who received a patent for a wiper design in 1903. Another claimant is Prince Heinrich, a brother of Germany's last Kaiser, who patented a system in 1908. Trico was created in 1917 shortly after company founder J. R. Oishei, knocked over a cyclist while at the wheel of his National Roadster in Buffalo, N.Y., one rainy night.

Oishei launched Tri-Continental Corp. to produce the Rain Rubber system he developed, which consisted of a vertical blade that was manually moved along the horizontal slot in the divided windshields of the day.

The arrival of one-piece windshields resulted in the development of a system that moved the wiper in an arc, and these were soon operated by vacuum drawn from the engine intake manifold. Twin-blades then arrived and were followed by novelties such as the Sleet Wand in 1928, an anti-icing wiper that employed rock salt encased in fabric.

Trico's first windshield-washer system appeared in 1936, and its first rear-window wipers in 1959.

So just how long can you get away with ignoring your wiper blades?

Bayley says Trico recommends replacement every six months. "If your wipers are still working effectively after a year, you're doing really well," he says. But, of course, they likely aren't really doing a good job.

The wear process is gradual enough that you might not notice until the point your forward vision is dramatically reduced by a blurred or streaked windshield. Replacing wipers is really a common-sense thing, Bayley says. "If you can't see properly, it obviously isn't safe."

Life for a wiper blade really is sadly short. To be effective the (usually) natural rubber blade has be both soft and have a sharply defined edge. It also has to be pressed with some firmness against the windshield, which is often a repository for dirt, salt and oil.

All of this, plus exposure to ultraviolet rays that can cause the rubber to split, rapidly reduces the effectiveness of the blade and can cause:

Streaking, created by hardened and cracked rubber.

Chattering, caused by the blade taking a permanent "set" while parked and no longer following the contour of the glass.

Edge wear, a rounding of the blade edge that reduces its ability to squeegee water off the screen.

Other problems include bent or broken wiper components often caused by ice scrapers and, sometimes, automatic car washes.

A wiper has three main components: the arm, which is the main metal section attached to the drive mechanism; the blade, which is the flexible superstructure that clips to the arm, and the refill, the actual rubber wiping element.

Replacing your wipers isn't particularly expensive, or difficult.

Wipers cost from about $10 each to perhaps $60 for some premium winter blades. But unless your blade is damaged you might be able to simply replace the refill for about half the price of a complete assembly. You have to know whether the blade fitted to your vehicle is the original type or an aftermarket replacement, though, in order to purchase the correct refill.

Fitting a blade or refill isn't exactly rocket science, and Car Care Canada says about 70 per cent of Canadians do just that, which saves the cost of installation. Buying the correct blade is easy. All you need are the make, model and year of your vehicle to reference the selector in the auto-parts store.

There are a wide variety of attachment devices in use, and while some can be tricky, most are easy enough to figure out and usually don't require tools. Trico's website (http://www.tricoproducts.com) has instructional videos you can use.

You should clean your windshield after installing new blades to avoid contaminating them with such things as tree sap, car-wash wax and road film. Make sure any cleaning product you use does not contain petroleum, which attacks rubber.

In my experience, the driver's side wiper often needs replacement before the passenger side (more crud on that side of the windshield?) but replacing both makes the most sense. Buying really cheap wipers that may not allow the rubber to follow the curve of the glass, or perhaps may lift off the glass at speed due to poor aerodynamic design, doesn't make good sense.

I've found winter blades, which were developed in the early 1950s, a good idea. Their rubber boots prevent ice and snow from clogging the blade mechanism and reducing its ability to keep the rubber section in even contact with the glass.

Confession time. I've never replaced a wiper blade until it was very obviously necessary, but the difference a new set of blades make is dramatic enough to prove just how dumb this is.