Mechanical wristwatches were invented around the mid-1500s, according to historians Alan Costa and Michael Murray of Mike's Clock Clinic. Early watches were crude and inaccurate, and had to be adjusted often. The invention of the quartz wristwatch can be traced to the 1960s, according to the Smithsonian Institution. This is a time difference of about 460 years between the two inventions
A mechanical watch uses no electricity. Rather, the power source is a wound-up spring. The spring releases its energy through internal gears, moving the arms. A quartz watch depends on electricity as the power source. A small battery powers internal electronics. When electricity is applied to a small piece of quartz, called a crystal, it vibrates. This vibration is sensed by other electronic components, which change the rate of vibration into time. Some quartz watches are called electro-mechanical. The vibration is used to drive gears, to move the hands. All-electronic watches have a numerical display, which displays the time as numbers.
As a general rule, precision mechanical watches costs far more than precision electronic watches. To make a mechanical watch requires a lot of very small gears, levers, and a spring. These cost time and money to make. All the internal components are assembled by a watchmaker, who has to be paid a wage. All this results in a very expensive watch. Precision electronics, on the other hand, is mass-produced cheaply. Modern robotics assemble the watches, so the cost of labor is reduced. Al this adds up to a watch being inexpensively made. The difference in cost sometimes exceeds thousands of dollars.
According to watch experts at Prestige Time, quartz watches are far more accurate than mechanical watches. The experts state that to achieve 99-percent accuracy in a mechanical watch is a feat. This is because heat, humidity, and nearby magnetic fields all affect the mechanism. Conversely, a quartz crystal vibrates very accurately when a voltage is applied to it. Overall, you can expect a mechanical watch to be off by 2 seconds per day, whereas a quartz watch is off by .02 seconds per day.