Let me tell you a ghost story: The electric saw was invented to facilitate sawing the pelvis to give birth

Although humans have been using saws for thousands of years, the modern electric saw has only been around for more than 200 years. Surprisingly, the electric saw was not originally invented for felling trees, but to facilitate childbirth.

Really, the first electric saws were only used to cut through the pelvis of women who had given birth…

Image source: pexels

Helps to prepare for childbirth

In ancient times, due to the underdeveloped science and technology, there were many cases of mothers or babies dying during childbirth. In terms of childbirth methods, childbirth is mainly divided into two types: normal delivery and caesarean section. In ancient China, normal delivery was the main method, and there were also very few cases of caesarean section, which was called "cesarean section" in "Historical Records".

Caesarean section is a last resort for mothers who are unable to deliver their babies due to pain or exhaustion. In April 1610, Jeremias Trautmann, a surgeon at the University Hospital of Wittenberg in Germany, performed the first modern caesarean section in the history of midwifery.

Since then, many women have died from heavy bleeding or infection during caesarean sections, and doctors in various countries have conducted experiments to improve the surgery in order to increase the survival rate of women and babies.

In early 1783, a Scottish female doctor ran into the office of her colleague John Att with her face covered. It turned out that the caesarean section she had just performed had failed, and both mother and child died. The family members were not satisfied and kept making a fuss. While Att was comforting her female colleague, she asked someone to notify James Jeffrey, a colleague at another hospital, to discuss a solution together.

18th century copperplate engraving of a caesarean section

After Jeffrey arrived, he first asked the female doctor to report to the dean and comfort the family members, and then discussed with At how to improve the cesarean section operation.

After careful study, they found that the cesarean section surgery that was popular at the time had two fatal flaws: first, doctors used a small saw and a knife to manually cut the woman's pelvis, which took more than 20 to 30 minutes to complete. Women who had been anesthetized were often awakened by the pain or even died from the pain; second, the woman would inevitably bleed heavily during the operation and eventually die from excessive blood loss.

What should they do? After repeated experiments, they came up with a bold idea: connect the knife and the saw with a chain and control the saw's speed by hand cranking. After more than a year of continuous improvement, the hand-cranked saw blade device became sophisticated and practical.

During the operation, when faced with a baby stuck in the birth canal, the doctor can manually crank a chain for a few minutes to cut the mother's pubic symphysis (a structure connected by fibrous cartilage between the two pubic symphysis surfaces on the front of the pelvis), separating the pubic bones on both sides, allowing the baby to be delivered from the uterus more easily.

After giving birth, mothers have to go through a painful recovery process: they are confined to a special hammock-like bed and cannot move until their wounds heal, which can last for more than ten days.

Because the device invented by Ater and his team had a sawtooth chain, later generations called it a hand chain saw. After it was powered by a gasoline engine, people called it an oil saw. The oil saw is the prototype of the modern electric saw.

The earliest simulation of a hand chain saw (Source: Public Domain)

In 1785, Art and Geoffrey jointly published the book "Principles of Midwifery and Postpartum Medicine". The book not only introduced in detail the pelvic incision (i.e. symphysiotomy) using a hand chain saw as the main tool, but also attached the principle and schematic diagram of the hand chain saw. The hand chain saw they developed was promoted in various European countries.

Market test and replacement

In the mid-19th century, with the development of industry, the demand for wood was increasing, and the development of logging tools became the focus of scientific attention. When Muir, an engineer in California, saw a doctor using a hand chain saw to perform a childbirth operation, he had an idea and developed a huge logging chain saw machine based on the doctor's hand chain saw.

The working principle of this machine is to perform the shearing action by the lateral movement of the staggered L-shaped blades on the saw chain. It weighs more than 100 kilograms and must be lifted by a crane to work. At that time, there were many innovative inventions in the West, but few could stand the test of the market.

Like the new chain saw machine invented by Muir, the spinning wheel saw developed by the British Hamilton in 1880 and the earliest chain-loop chain saw invented by the American Bence in 1905 were all eliminated from the market one by one because they were too bulky, too costly or too inefficient.

In 1926, when Andre Steele, a German businessman who was an engineer, founded a boiler factory in his hometown of Stuttgart, he needed a lot of wood as raw materials, so he started to develop the most economical and affordable logging tools. After carefully studying the chain saws invented by Art, Muir, Bence and others, he finally designed the world's first electric-powered special logging chain saw.

This electric chain saw weighs about 50 kilograms and has a working horsepower of 3 kilowatts. It can cut down trees with a diameter of about 1 meter and can be easily operated by two people. He calls this electric chain saw an electric saw, also known as a power saw.

Andre Steele and his improved chainsaw (Source: Electric Chain Saw Network)

Steele was a man with a forward-thinking mind. When he discovered that electric saws were very helpful in logging, he improved the electric saw and had the factory mass-produced it while applying for a patent for the invention of the electric saw.

All these benefited Steele and the chainsaw factory he founded: his company was ranked first in the world in chainsaw production for many years, and he was therefore honored by later generations as the "Father of the Chainsaw."

Versatile, lightweight and efficient

Since Steele invented the new type of chainsaw, countries around the world have started a craze for improving chainsaws, which has lasted for decades.

In 1959, 9 years after STIHL launched the first truly one-person chain saw, a product that changed the landscape of the chainsaw industry - the Canny light oil chain saw - was launched.

This oil chain saw adopts direct drive for the first time, without a bulky and heavy gear box, and the weight of a single saw is less than 20 kg. It looks very similar to modern electric saws, and the design concept is also very advanced.

In the following decade, global chainsaw production has grown rapidly. By the early 1970s, with the widespread use of small internal combustion engines, chainsaw production has changed from being large and heavy to being light and efficient. The United States, Sweden, Japan and other countries have mass-produced chainsaws that can be operated by one person.

Kangli Light Oil Chain Saw

Today, due to the needs of production and life, people have adopted advanced technologies such as hydraulic transmission and ice crystal blades to develop different types of electric saws, such as one-handed saws, concrete cutting saws, high branch saws, etc.

Due to different uses and operations, these chainsaws are divided into fixed and portable types. The toothed saw blades are generally made of pure steel and are available in strip, round, chain, etc. In the cartoon "Boonie Bears", the one that Bald Qiang uses to chop trees all day long is a portable chainsaw.

Image source: pexels

Interestingly, as science develops, cesarean sections have replaced the original symphysiotomy, so among the many uses of modern electric saws, none is used to cut the mother's pelvis to facilitate the birth of the baby. If the two Scottish doctors who invented the hand chain saw were in heaven, what would they think?

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Editor/Xiao Xitushuo