This article discusses contribution of engineering technologies through years. It is achievements and advances in engineering that changed all. The development of safe drinking water supplies, sanitary sewer systems, and wastewater treatment schemes drastically reduced diseases that were rampant a hundred years ago, and so reduced infant mortality. Mechanical engineering has changed the quality of life significantly from that of a century ago. Air conditioning, which was developed early in the 20th century to control humidity in plants, factories, and mills where manufacturing processes were affected by too damp a sheet of paper or too dry a spool of thread, was widely domesticated in the second half of the century. Air travel is similarly comfortable and even safer, and few of my generation grow anxious even when flying across the country or around the world. The level of engineering accomplishment and dependability embodied in our terrestrial travel seems to be rivalled only by that achieved in space travel, a distinctly 20th-century engineering achievement.
My grandparents were born in the late 19th century and my parents in the early 20th. During my own childhood, whenever 1 visited the homes in which they grew up, I was given a glimpse of how much 20th century advances in engineering have contributed to o quality of life.
My father’s boyhood home in Pennsylvania had an outhouse in the backyard, placed as far from the back door as the small lot would allow. He often told stories of how uncomfortable it was to use that outhouse in the middle of winter. By the 1940s, plumbing had been added to the house, but the new bathroom was located on the back porch, so that we still had to go outside to get to it.
The principal source of heat in the mornings was the coal stove positioned away from the kitchen wall. It was great to make toast over an open fire, but not so enjoyable to take a bath in a galvanized tub set out on the floor and filled with water heated on the nearby stove. A small mirror and a leather strop were hung nearby so that my grandfather could be close to the source of hot water when he shaved. The only time I saw my father use a straight razor was when we visited my grandpa’s house.
In the evenings, aunts and uncles would visit and everyone would sit around the large kitchen table and reminisce about the good old days. They remembered sitting together around their first radio, but not all memories were warm ones. The conversation would become hushed when they remembered grandpa’s early death from black lung disease or the deaths of infant brothers and sisters they hardly got to know.
Ice and Ashes
My mother’s girlhood home was in a larger city in upstate New York. It had more modern plumbing but still no refrigerator. The iceman brought blocks of ice in a horse-drawn wagon. He was such a regular visitor that he just let himself into the kitchen and placed the fresh ice directly into the icebox near the door. The water from the melting ice was caught in a pan beneath the icebox, but someone had to remember to empty it.
Henry Pelroski is the A.S. Vesic Professor of Civil Engineering and a professor of history at Duke University. He is the author of Remaking the World, and other hooks about engineers, engineering, and technology.
Coal was delivered to the basement by the ton, and the furnace had to be fed in the morning and stoked in the evening if heat was to be had. Ashes needed to be emptied and disposed of. As late as the 1950s in New York City, where I grew up, we also had coal stoves and iceboxes in the kitchen. Water had to be emptied regularly, and ashes had to be hauled to the curb and kept separate from garbage for pickup.
At mid-century, air conditioning was still a novelty that we experienced mostly in movies and department stores. Television was a luxury that many of us had seen only in an appliance store window, or in the house of a neighbor who had gotten lucky in a raffle. Telephone service was limited, often to a party line, and making a long-distance call was not something done casually or without an operator. Mail within larger cities was delivered twice a day, but an airmail stamp had to be affixed if a letter going across the country was to arrive at its destination in a reasonable amount of time.
____nobiles were unnecessary in a city with streetcars and subways, but it was nice to have a car to go for drives on the weekend or to visit grandparents in the summer. However, cars then had brakes that locked and cooling systems that overheated. Auto trips seemed full of uncertainties and dangers. There were no interstate highways, and so the trip was long and complicated. The airplane was not an option that came readily to mind, even for a transatlantic crossing.
It is achievements and advances in engineering that changed all this. The development of safe drinking water supplies, sanitary sewer systems, and wastewater treatment schemes drastically reduced diseases that were rampant a hundred years ago, and so reduced infant mortality. Radio and television have become commonplace, if not ubiquitous, and calling around the world on a cell phone has become a recreational activity. The mail has increasingly brought catalogs instead of letters, communication with family and friends having become virtually instantaneous via e-mail.
Mechanical engineering, in particular, has changed the quality of life significantly from that of a century ago. Coal and its polluting soot and ashes are a thing of winters past, with oil and gas burners and heat pumps providing warmth to every room in the house, not just the kitchen. The furnace in the basement or crawl space beneath our home hardly needs attention, nor does the hot-water heater nearby. That pressure vessel is not likely to blow up as so many steam boilers did around the turn of the century, because safety is demanded and ensured by the Codes and Standards of ASME. Where our hot water or heat come from is seldom even thought about, because of automatic thermostats. The one for our furnace can even be programmed to provide just the right amount of heat at different times of the day and night. When summer comes and we wish to be cooled, we need at most to flip a switch on the thermostat.
Air conditioning, which was developed early in the 20th century to control humidity in plants, factories, and mills where manufacturing processes were affected by too damp a sheet of paper or too dry a spool of thread, was widely domesticated in the second half of the century. Older homes and office buildings became fitted with room air conditioners and newer construction with integrated central air conditioning. It has become expected, in certain climates at least, that indoor temperature and humidity be controlled for our comfort.
The wide adoption of air conditioning has been credited with the influx of population into the southern United States and, hence, in part with the economic prosperity enjoyed by that part of the country. It is certainly difficult to imagine that Atlanta or Houston would be what they are today without air conditioning. Indeed, just as northern cities have developed enclosed and heated walkways and tunnels between downtown buildings to get their citizens through tough winters, so the southern cities have developed enclosed and cooled connectors between their downtown buildings to keep the summer at bay. None of these measures would be so effective were it not for the efficient and reliable air conditioning systems developed by mechanical engineers.
Iceboxes have been replaced by refrigerators with freezers, abundantly full of the products of mechanized agriculture and refrigerated transport. At first, home freezers had to be defrosted regularly to remove the ice that had built up in them, something that was as messy and tiresome a chore as cleaning an oven. Now, of course, freezers are self-defrosting, as ovens are selfcleaning. Refrigerators and appliances generally are energy efficient. Ice houses are a thing of the past, and ice cubes for domestic use are made automatically and can be dispensed automatically without the freezer door even having to be opened.
Over the past century, automobiles have advanced from tough-tired horseless carriages to smooth-riding living rooms, with comfortable adjustable seats, excellent climate control, static-free radios that automatically find the strongest stations, and tape and compact-disc players of exceptional quality. We need not carry a box of tools and be a mechanic to take a thousand-for the car we drive seldom breaks down. It needs little service or gasoline and has safety features like crumple zones, seat belts, and air bags that absorb energy and protectus even when we missteer.
Air travel is similarly comfortable and even safer, and few of my generation grow anxious even when flying across the country or around the world. The level of engineering accomplishment and dependability embodied in our terrestrial travel seems to be rivaled only by that achieved in space travel, a distinctly 20th-century engineering achievement. Though some might argue that putting men on the moon and planetary exploration have affected us little on Earth and have contributed little to our quality of life, that is a shortsighted view.
I am an engineer today because the Soviet Union put the first artificial satellite into orbit in 1957. Sputnik shocked the United States into accepting one of the most ambitious engineering challenges of all time-—to put a man on the moon within a decade. The Apollo program is a model of engineering, something that had to work the first time it was tried, for there was no way to test completely on Earth a system that had to do what the command module and moon lander had to do in space.
I was in high school in the late 1950s, unsure of what I would do after graduation. I was good in science and math, and so to study those subjects in college seemed natural. The launching of Sputnik highlighted the need for engineers, however, and it was engineering that I was advised to study, as were countless other college-bound students at the time. I have never regretted the modern liberal education that I received as an engineering student, and I am grateful that my knowledge of engineering has enabled me to appreciate, perhaps somewhat more than nonengineers can, what we have experienced technologically in the latter half of the 20th century.
No Mistake About It
Engineering achievements have always been interdisciplinary, with the technical tempered by the economic, esthetic, and social constraints that no human endeavor can escape. What distinguishes engineering, however, is its predictive power. When engineers calculate that a space vehicle will need a certain amount of fuel to reach the moon and return, they must not be wrong, for there are no service stations en route. The cost of the launch may escalate, the appearance of the vehicle may be questioned, and the social goals of the project may be debated, but the technical details cannot be wrong. Engineers take this as the fundamental challenge of their profession, and they meet it admirably, now often aided by digital computers.
The computer, of course, has been one of the most far-reaching achievements of the last several decades, and it now pervades our lives. The mass production of integrated circuits and other parts essential to the operation of the computer and its connection to the World Wide Web through the Internet owes much to mechanical engineering, but the success of the computer and the systems in which it is embedded emphasize the interdependence of all branches of engineering.
Computer-aided design and other computer-aided technologies are being used by engineers of all stripes, and they have provided the tools to design structures with a complexity that was untried in slide-rule days. Jet aircraft, such as the Boeing 777, can now be designed and manufactured by international teams with finer tolerances and more reliable systems than ever before.
New materials and diagnostic devices have revolutionized medical care, with hip and other joint replacements being ordinary and with noninvasive evaluations being expected. Bioengineering, in part nersliip with the medical profession, has enabled us to live longer, healthier lives, and our children can look forward to even further benefits. Life in the new millennium can indeed be expected to be longer still and certainly more comfortable than it was a hundred years ago, thanks largely to the work and achievements of engineers and engineering.