In the 1920s and 1930s oxygen was a potentially useful, but possibly non-essential, assistant technology for the mountaineer.
Having come to London and the Royal College of Art from his home in Wales to paint in his 20s, Dawson instead found himself the essential daily assistant to the great British artist in his final spectacular burst of energy.
Graduate and teaching assistants are essential to the University of Toronto's teaching.
At CEWA schools, Aboriginal Teaching Assistants are essential links to community, not only supporting Aboriginal students, but also fostering school-community engagement and connections.
Front-line workers such as medical assistants are essential to a smoothly operating health care practice, but their roles are rarely discussed.
A good team of research assistants is essential for successful recruitment and high quality data collection.
"Exposure to silica can be deadly, and limiting that exposure is essential," said David Michaels, the assistant secretary of labor in charge of OSHA.
"If you want to stabilize CO2 emissions over a long period of time, we think carbon sequestration is essential," said Robert S. Kripowicz, acting assistant secretary of energy for fossil energy.
A trusty assistant is essential for this phase of the installation, and if your apartment is a few floors from where you are putting the dish, I recommend placing her near a window and equipping her with a whistle loud enough to be heard on the roof, where you will be stationed dishside with a socket wrench and that precision compass.
These are close quarters, as Ms. Brook shares space with her daughter, Amanda, 17, and an assistant, but essential if you check the animals throughout the night and take the three camels for walks around the neighborhood at 6 30 in the morning.
