Overview:
“Diggers in the Earth” by Eva March Tappan delves into the world of mining, exploring how various essential materials are extracted and transformed into the products we use daily. The book takes readers on a journey through coal mines, granite quarries, and gold diggings, revealing the history, processes, and dangers associated with these industries. Tappan highlights the evolution of mining techniques, from manual labor to the use of steam, compressed air, and electricity, showcasing the constant drive for innovation and efficiency.
Beyond the technical aspects, Tappan emphasizes the human element involved in mining, acknowledging the hard work, risks, and ingenuity of the individuals who make these industries possible. She also underscores the importance of these materials in our lives, demonstrating how our modern world is built upon the foundation of extracted resources.
Key Findings:
- Mining processes have significantly evolved over time, shifting from manual labor to more efficient and mechanized methods.
- The search for resources often involves significant risks, from cave-ins and gas explosions in coal mines to the unpredictable nature of veins in gold and silver mines.
- Extraction processes are constantly being refined to improve efficiency and minimize waste, with new technologies continually emerging to address challenges.
- Metals play a vital role in various industries, from construction and transportation to manufacturing and technology.
- Resource extraction is a crucial part of our global economy, impacting the development and progress of societies worldwide.
Learning:
- Coal Mining: Learn how coal was formed millions of years ago from decaying plant matter in swampy environments. Discover the dangers of coal mining, including cave-ins, poisonous gases, and the potential for explosions. Explore the evolution of mining methods, from manual labor to the use of machinery and safety lamps. Gain insights into the various types of coal and their applications.
- Granite and Marble Quarrying: Understand the formation of granite and marble, composed of different minerals. Learn about the techniques used to extract these stones from quarries, including blasting, drilling, and splitting. Discover the various uses of granite and marble, from building materials to decorative elements.
- Concrete: Learn how concrete is made from a mixture of Portland cement, sand, and aggregate. Understand the importance of using quality materials and proper mixing techniques for strong and durable concrete. Explore the advantages of concrete as a building material, including its fireproof nature and versatility.
- Brickmaking: Discover the process of brickmaking, from tempering clay to drying and firing the bricks. Learn about different types of bricks, their uses, and the importance of quality control.
- Gold Mining: Understand the history of gold mining, from panning for gold in placers to the use of hydraulic mining and dredges. Learn about the challenges of extracting gold from quartz veins. Explore the different methods used to separate gold from other minerals, including amalgamation and cyanide processes.
- Silver Mining: Explore the history of silver mining, focusing on the famous Comstock Lode in Nevada. Discover the dangers faced by miners, including cave-ins, water, and heat. Learn about the various methods used to extract and process silver, including crushing, amalgamation, and smelting.
- Iron and Steel Production: Understand how iron is extracted from ore through the use of blast furnaces. Discover the process of transforming iron into steel using the Bessemer and open-hearth methods. Learn about the properties of iron and steel, their uses, and the challenges associated with their production.
- Copper Mining: Explore the history of copper mining, from the use of native copper by indigenous populations to modern extraction techniques. Learn about the different types of copper ore and their processing. Discover the various uses of copper, from electrical wiring to alloys like brass and bronze.
- Aluminum Production: Understand the discovery of aluminum and the development of the Hall-Héroult process for its production. Learn about the mining of bauxite, the primary source of aluminum. Explore the properties of aluminum, including its lightweight nature, strength, and resistance to corrosion. Discover the diverse uses of aluminum in various industries, from transportation to consumer goods.
- Petroleum Extraction and Refining: Learn about the formation of petroleum, its extraction from sandstone formations, and the challenges associated with oil drilling. Understand the process of refining crude petroleum into various products, including kerosene, gasoline, and paraffin. Explore the numerous uses of petroleum products in our modern society.
- Salt Mining: Discover the history of salt mining, focusing on the unique Wieliczka Salt Mine in Poland. Explore the various methods used to extract salt, including mining, evaporation, and brine extraction. Understand the importance of salt in our diet, agriculture, and industrial processes.
Historical Context:
- The text was written in 1916, a time of significant industrial growth and innovation.
- The discovery of gold in California in 1848 triggered a gold rush that led to the development of new mining techniques and the expansion of mining operations across the American West.
- The use of electricity was rapidly expanding in the early 20th century, creating a demand for copper for electrical wiring and other applications.
- The development of the automobile industry in the early 1900s led to increased demand for aluminum due to its lightweight and durable properties.
- Petroleum extraction and refining technologies were rapidly evolving in the early 1900s, leading to increased production and the development of pipelines for efficient transportation.
Facts:
- Coal Formation: Coal was formed millions of years ago from decaying plant matter in swampy environments. Water and pressure over time transformed the organic matter into coal.
- Granite Composition: Granite is composed of three primary minerals: quartz, mica, and feldspar.
- Marble Formation: Marble is formed from limestone that has undergone transformation through heat and pressure.
- Concrete Ingredients: Concrete is made from a mixture of Portland cement, sand, and aggregate (broken stone or gravel).
- Brickmaking Clay: Clay, a mixture of alumina and silica, is the primary ingredient in brickmaking. The quality of the clay determines the properties of the brick.
- Gold Nuggets: Gold nuggets are large, solid pieces of gold that are sometimes found in placer deposits or quartz veins.
- Silver and Sulphur: Silver is prone to tarnishing because it reacts with sulphur, forming a black sulfide.
- Iron Abundance: Iron is one of the most abundant elements in the Earth’s crust, making up about one-twentieth of its composition.
- Copper in Ancient Times: Native copper, readily available in northern Michigan, was used for tools and weapons by indigenous populations in North America long before European colonization.
- Aluminum Discovery: Aluminum was discovered in the 19th century and became widely available thanks to the development of the Hall-Héroult process for its electrolysis.
- Petroleum Formation: Petroleum is thought to have been formed from organic matter, primarily marine organisms, that was buried under sediment and subjected to heat and pressure over millions of years.
- Salt in Ocean Water: Approximately one-thirtieth of ocean water is composed of salt, making it a major source for salt production.
- Rock Salt Deposits: Rock salt deposits, formed from the evaporation of ancient seas, are found in various locations around the world, including the United States.
- Salt as Money: Cakes of salt have been used as a form of currency in some parts of Africa and Asia.
- Salt as a Preservative: Salt has been used as a preservative for food for centuries, preventing spoilage and extending shelf life.
Statistics:
- Comstock Lode Production: The Comstock Lode in Nevada produced over $340 million in gold and silver between 1860 and 1890.
- Ontonagon Boulder Weight: The Ontonagon Boulder, a massive piece of native copper, weighs over three tons.
- Copper Stamp Mill Capacity: Modern copper stamp mills can crush up to 500 tons of ore in less than 24 hours.
- Sulphuric Acid Production: Fumes from roasting copper ore can be captured and used to produce sulphuric acid.
- Aluminum Production Cost Reduction: The Hall-Héroult process reduced the cost of aluminum from $12 per pound to 18 cents per pound.
- Lakeview Gusher Production: The Lakeview gusher in California produced up to 50,000 barrels of oil per day at its peak.
- Salt Production in the United States: In 1913, the United States produced over 34 million barrels of salt.
- Great Salt Lake Water Salinity: The water in Great Salt Lake is significantly saltier than ocean water.
- Salt Production at Salton: The Salton salt fields in California cover over 1,000 acres and can produce up to 20 inches of salt after evaporation.
- Michigan Rock Salt Stratum: A rock salt stratum in Michigan is estimated to be between 30 and 250 feet thick and located 1,500 to 2,000 feet below the surface.
Terms:
- Bituminous Coal: A type of coal that is dull and smutty, containing more bitumen or mineral pitch.
- Anthracite Coal: A type of coal that is hard and bright, burning with a glow but not a blaze.
- Gangue: The worthless rock that surrounds valuable minerals in a vein.
- Amalgam: A mixture of mercury and a precious metal, such as gold or silver.
- Scoria: Slag or waste material produced during smelting.
- Cryolite: A mineral that melts easily and can dissolve alumina, used in the production of aluminum.
- Bauxite: The primary ore source of aluminum.
- Petroleum: Crude oil, a naturally occurring mixture of hydrocarbons found in underground formations.
- Kerosene: A refined petroleum product used as a fuel for lamps.
- Brine: A solution of salt in water, often extracted from underground formations or salt springs.
Examples:
- Coal Mining: Tappan describes the dangerous work of miners in coal mines, highlighting the risk of cave-ins, gas explosions, and the use of safety lamps to minimize the dangers.
- Granite Quarrying: The author provides a vivid description of the process of splitting large blocks of granite using the plug-and-feather method.
- Concrete Construction: Tappan outlines the construction of a concrete house, emphasizing the importance of proper mixing techniques and reinforcement for strength and durability.
- Gold Digging: The text recounts the gold rush to California in 1848, describing the methods of panning, cradling, and hydraulic mining.
- Silver Mining: The author details the history of silver mining on the Comstock Lode in Nevada, highlighting the challenges faced by miners due to the unpredictable nature of veins, cave-ins, water, and heat.
- Iron Production: Tappan describes the immense blast furnaces used to melt iron ore and the spectacle of “tapping” the furnace to release the molten iron.
- Copper Smelting: The text highlights the intense heat and dangerous nature of copper smelting, describing the process of pouring molten copper into moulds.
- Aluminum Production: Tappan illustrates the process of aluminum production, from mining bauxite to the electrolysis of alumina in molten cryolite.
- Petroleum Extraction: The author describes the process of drilling oil wells, from the initial stages of drilling to the discovery of gushers and the challenges of handling and storing large quantities of oil.
- Salt Mining: The text recounts the history and operation of the Wieliczka Salt Mine in Poland, a fascinating example of a mine with underground structures carved from salt.
Conclusion: “Diggers in the Earth” offers a comprehensive overview of the world of mining, highlighting the history, processes, challenges, and significance of resource extraction. From the formation of coal and marble to the production of iron, aluminum, and copper, Tappan skillfully explains the complex processes involved in bringing essential materials from the Earth’s depths to our daily lives. The book emphasizes the importance of innovation and technological advancements in improving mining techniques and minimizing environmental impact. It also acknowledges the human element of mining, paying tribute to the skilled workers who face risks and overcome challenges to provide us with the resources we rely upon. Through vivid descriptions and insightful observations, “Diggers in the Earth” provides a fascinating glimpse into the world of mining, leaving readers with a newfound appreciation for the efforts that bring us the materials that shape our modern world.