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"On This Day" In Engineering History

Tune in to find out about significant engineering events that took place "on this day".

October 31, 1941 – The Completion of Mount Rushmore

Posted October 31, 2013 8:00 AM by cheme_wordsmithy

One of the fondest memories I have from my "Out West" trip 6 years ago was arriving at the Mount Rushmore National Memorial in South Dakota. Though I am often more impressed by the creations I witness in nature, the massiveness of this engineering marvel and work of art was pretty amazing to see.

The face of this structure stretches 60 feet, making it the largest art sculpture project on earth. The memorial consists of the faces of four of our nation's presidents, George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln (respectively), immortalized in granite.

Jonah LeRoy "Doane" Robinson was credited with conceiving the idea behind Mount Rushmore, which was to carve famous people into the Black Hills of South Dakota to promote tourism. Initially, the plan was to sculpt some western heroes like Louis and Clark into granite pillars known as the Needles. However, Gutzon Borglum, the Danish-American artist and sculptor responsible for Mt. Rushmore , realized that both the setting and the subjects were too thin. He decided to memorialize the four presidents instead, for a more national focus, and to do so on Mount Rushmore, for better quality stone and more exposure to sunlight. After securing federal funding, the project began on October 4, 1927.

The Mt. Rushmore project team included nearly 400 men and women. Each would walk 700 stairs to the top of the mountain every day to punch in for duty at $8.00/day or so. Drillers operated jackhammers, powdermen placed dynamite, and others operated the winch house or acted as spotters in hoisting workers off the mountain. While there were some injuries, surprisingly there were no fatalities throughout the project.

Work on Mt. Rushmore - Via

The sculpting process involved the use of dynamite (and lots of it) to blow rock apart. About 90% of Mt. Rushmore was carved with dynamite. When only 3 to 6 inches of rock remained to be removed at each surface, workers would drill holes very close together to weaken the granite and eventually pull it off by hand or by hammer. This process was called "honeycombing." In fact, workers would often sell honeycombed pieces of granite to tourists visiting the construction. To finish and smooth the surface, workers used a hand-facing or bumper tool.

The four faces of the monument were completed by 1939. The original plan was to sculpt each president down to the waist (see model on left), but due to lack of federal funding the project was forced to end in October 1941. And although it never reached its full imagined potential, the memorial is still a wonder to behold today, and is a proud symbol of America and some of the important men who helped build and preserve it.


National Parks Service

Engineering Pathway

6 comments; last comment on 11/02/2013
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March 11, 1960, Pioneer V Launched from Cape Canaveral

Posted March 11, 2013 12:07 PM by LakeGrl
Pathfinder Tags: March 11 on this day pioneer 5 space

Pioneer V (also known as 1960 Alpha 1, Pioneer P-2, and Thor Able 4) was launched from Cape Canaveral, Florida, as one of the first attempts to study the solar system. It was a spin stabilized space probe and carried into space on a Thor-Able three stage rocket. The Pioneer V was approximately the size of a beach ball and was equipped with four solar cells that recharged the on-board batteries. The Pioneer V entered an orbit around the Sun between Earth and Venus and provided a wealth of data on interplanetary space such as magnetic fields, cosmic radiation, electrical fields and micrometeorites. It was stabilized by slowly spinning about its axis. The spacecraft transmitted information until 26 Jun 1960 when it was 22.5 million miles (36 million km) from Earth.

We have come a long way since the Pioneer V days of early space exploration. And we have learned much more about sun spots, magnet fields and cosmic radiation. The Pioneer V may look simple compared to the satellites and mars rovers of today, but it served its purpose well. The Pioneer V was the most successful in the Pioneer/Able missions.



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October 24, 1836: Alonzo Philips Patents Friction Matches

Posted October 24, 2012 1:00 PM by SavvyExacta

Alonzo Philips of Springfield, Massachusetts patented the friction match consisting of phosphorus, chalk, and glue. His creations were called Locofocos. Phillips' work followed that of English pharmacist John Walker who in 1827 produced yard-long lightable sticks that can be considered the real precursor of today's match.

Phillips described the process in Specification of Letters Patent No. 68:

"I take one ounce of glue and dissolve it by the aid of water and heat in the usual manner; to this glue I add four ounces of finely-pulverized chalk or Spanish white, stirring it in so as to form a thick paste. I then put in one ounce of phosphorus, keeping the materials at such degree of heat as will suffice to melt the phosphorus and incorporate the whole together. Into this composition the matches are dipped after being previously dipped in sulfur in the usual manner."

Philips grouped the matches in slabs and put them between two pieces of paper to avoid accidental ignition. In 1855 Carl Lundstrom of Sweden produced the first red phosphorus "safety" matches.


Idea Finder

Today in Sci


1 comments; last comment on 10/25/2012
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August 12, 1865: Lister Performs First Surgery with Antiseptic

Posted August 12, 2012 12:00 AM by SavvyExacta

Joseph Lister was inspired to stop the spread of germs in surgical wards after reading Louis Pasteur's work on the souring of wine. He thought that disease was spread by microbes carried in the air and was concerned about germs entering skin that had been cut open. He began to use a carbolic acid spray on patients as a chemical alternative to heat, reducing the death rate from 45.7% to 15%.

In his work as professor of surgery at Glasgow University, Lister considered ward cleanliness to be very important. He followed the earlier work of Dr. Ignaz Semmelweiss from Hungary who required his doctors to wash their hands in calcium chloride between patients. Lister first advocated the spraying of carbolic acid in the air to kill germs. His assistants utilized a sprayer to administer the carbolic acid, enveloping the surgery in a yellow mist with a tar-like smell.

On August 12, 1865, Lister took cleanliness a step further by cleaning the actual wounds. His first treatment was on patients with compound fractures where gangrene was a common cause of death due to the bone breaking through the skin. He covered the wounds with lint soaked in carbolic acid and increased survival rates.

James Greenlees, an 11-year-old boy with a compound fracture of the tibia and fibula, was the first to receive the treatment. His wounds were treated with the carbolic acid plan and he was discharged on October 2, 1865. Lister extended the use of carbolic acid to washing his hands and soaking surgical tools in it. The process is known as antiseptis, or preventing infection. Lister is known as the father of antiseptic surgery.


Encyclopedia of World Biography - Joseph Lister Biography

History Learning Site - Joseph Lister

sciencemuseum - Carbolic steam spray used by Joseph Lister, England, 1866-1870 [image]

University of Glasgow - On This Day: 12th of August

1 comments; last comment on 08/16/2012
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July 12, 1960: Etch A Sketch First Produced in U.S.

Posted July 11, 2012 12:00 AM by SavvyExacta
Pathfinder Tags: etch a sketch history July 12 toys
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Did you have an Etch A Sketch as a child? The toy, created by French inventor Andre Cassagnes, first rolled off the factory line on July 12, 1960. Although the toy's exterior has been available in different colors, the inner workings remain the same.

Invention and Sale of the Etch A Sketch

Many references cite Arthur Granjean as the inventor of the Etch A Sketch. According to Ohio Art's website, the inventor was Andre Cassagnes. So who was the actual inventor? It was Cassagnes, who did not have the money to register his patent. Eventually, Paul Chaze invested in the toy. Chaze's accountant Arthur Granjean filed the patent and his name became associated with it.

Cassagnes developed the toy in the late 1950s and named it L'Ecran Magique (The Magic Screen). Chaze convinced Cassagnes to relinquish his rights to the toy outside France for $10,000. It was first marketed in England as the DoodleMaster Magic Screen and was eventually bought by the Ohio Art Company and marketed under the name we know today.

How the Etch A Sketch Works

  1. Horizontal and vertical knobs are turned
  2. A pulley system moves an internal stylus
  3. The stylus "etches" a sketch onto an aluminum powder-coated glass window
  4. Styrene beads move powder evenly to erase the drawing when the toy is shaken

Etch A Sketch Facts

  • One of the first toys advertised on TV
  • 150 million sold in the U.S.
  • An image can be made "permanent" by drilling a hole in the back of the toy and removing the aluminum powder and plastic beads

Resources: - Inventor of the Week: Arthur Granjean

Idea Finder - Etch a Sketch

Ohio Art - Our Story

Today I Found Out - How an Etch A Sketch Works

Wikipedia - Etch A Sketch

Wired - July 12, 1960: Etch A Sketch? Let Us Draw You a Picture [image]

6 comments; last comment on 07/15/2012
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