Windshields are one of those standard features on cars that the modern driver doesn’t think too much about unless they are either excessively dirty or cracked from a flung rock. We rely on the windshield to not only block the wind, but to keep the rain off, keep the bugs out and protect us from those flung rocks. Though the windshield is a standard and often required car part these days, it did not start out that way.
Early Automobiles and the Dubious Plate Glass Windshield
Though gas powered cars came on to the scene in the early 1890s, they were basically designed the same way as horse-drawn carriages—minus the horses—and didn’t have windshields for over a decade. The cars had relatively simple designs featuring not much more than bench seats and a steering wheel. They also didn’t go terribly fast. If you were worried about protecting yourself from the elements you wore goggles and a duster type jacket.
It wasn’t until 1904 that the first car windshield was introduced, and they were not standard on any vehicles until Oldsmobile in 1915. These early windshields were a far cry from the gently curved models we see in cars today. They were usually divided into two panels, so when one became dirty, the driver could fold the upper layer down and continue on their merry way. In addition to the simpler shape, these original glass windshields were made from ordinary plate glass, and would shatter on impact: a design flaw that certainly did not enhance its safety record.
Looking for a Workout? How About Some Early Windshield Wipers
The earliest examples of windshield wipers on cars didn’t come about until 1916—over a decade after the first windshields. As with everything in these original cars, some of the first examples of windshield wipers, known as Folberths, were rudimentary at best, requiring the driver to hand crank them.
Interestingly enough, hand-cranked windshield wiper technology had existed since 1902. Inventor Mary Anderson became irritated by the constant stops her streetcar conductor had to make to get out and clear off the windshield in inclement weather, so she developed a wiper blade that could be operated inside of the streetcar. She patented her “Window Cleaning Device” in 1903, and despite offering it to manufacturing companies to adapt for automobile production—especially now that they were starting to have windshields—there were no takers.
Shatter Proof Glass: The Beginnings of Windshield Safety and Modernization
In 1903, the original laminated glass was inspired by a happy accident in the laboratory of Édouard Bénédictus. The story goes that a flask was mistakenly shattered that had a layer of plastic cellulose nitrate from a previous experiment dried on it. Instead of exploding everywhere into many shards, this beaker instead stayed together, with the cellulose nitrate preventing the pieces from flying apart. Though this discovery was made in 1903, Bénédictus didn’t file for a patent for his safety glass until 1909 after hearing about people injured from broken plate glass in an automobile accident.
This original safety glass proved difficult and expensive to manufacture, but it led to further safety glass innovations. Tree cellulose was used as a more economical means of producing laminated glass in the early 1900s, but the real innovation was the invention of the plastic polyvinyl butyral (PVB) by Howard Matheson and Frederick Skirrow in 1927. By 1936, manufacturers had discovered that laminating PVB between two layers of glass created an economically sound safety glass that resisted yellowing and penetration from debris in car accidents. Safety glass was required in all cars beginning in 1937.
How About Some Curves: Split Windshields and Today’s Curved Windshields
Though car windshields became much less likely to injure someone due to safety glass, they were still a far cry from what we see today. For example, 30’s Cadillacs had a split V type windshield made of two panels of glass that met in the center of the front of the car. These windows were still not fully attached and could be vented. Windshields made of two panes of glass in a wide V shape offered better visibility to a fully straight windshield, and became more standard in new cars until curved glass manufacturing became more readily available.
The 1934 Chrysler Imperial Airflow CW was the first car to offer the option of a single sheet of curved windshield glass, and as time went on it became more and more common for curved glass to be the standard for windshields. In 1934 Studebaker’s Starlight had a curved windshield. In the 50s GM’s LeSabre featured the first panoramic windshield that reduced the blind spots from the car’s support pillars. By 1957, curved windshields were the norm rather than the exception.
Safety First: Ralph Nader and the NHTSA’s Impact on Windshields
During the 1960s there was an even greater push—spearheaded by consumer safety advocate Ralph Nader—to ensure that car safety was of paramount importance when designing cars. In addition to creating the National Highway Traffic Safety Administration (NHTSA) vehicle safety standards were made more stringent across the board, including in the areas of roof rigidity during rollovers and in the strength of the safety glass in windshields. These standards are still strictly adhered to today, and have led to further increases in standard car safety features to protect passengers like airbags and seatbelts.
The Mystery of the Dots: Why Do Modern Windshields Have Those Anyway?
So we now know all there is to know about the evolution of windshields. From plate glass to safety glass, from straight to curved and ever more securely laminated. But the real question that bothers modern auto enthusiasts is what is the deal with those little dots along the edges of the windshield? From where the glass is securely glued down to the frame there exists a series of small black dots or other designs around the edges of the glass, visible from the inside of the car.
The first thing to know is that the black band around the edges of the windshield that includes these dots is known as the “frit.” This is a type of ceramic paint that is baked on to the glass that not only covers up the unsightly glue that is used to hold the windshield on, but it helps to protect that glue from the damages of the sun’s UV rays. The frit helps the adhesive to stick more securely to the glass, and the glass to stick more securely to the car. The most important thing about the dots on the frit, however, has to do with heat distribution.
When auto glass is formed, it is first formed straight and then heated and curved. When the auto glass (complete with that black band) is heated, the black part becomes hotter much faster than the rest of the glass, which creates a distortion around the edges of the glass where the clear part and the black band meet. The gradient of dots help to even out the temperature differences of the glass where these two parts meet, both preventing and helping to hide any distortion of the glass that this uneven heating may cause.
Windshields: The Unsung Heroes of A Pleasant Car Ride
It may seem impossible to imagine a car without a windshield, but as we have seen it took decades of trial, error, and innovation to create the safe, functional windshields we take for granted in our cars today. Every time you curse a particularly large bug splattered on your windshield or a bird with particularly good aim, just remember that in 1900, that nasty mess would be on you.
