Yogurt stands in for mayonnaise, and veggies such as celery, onions or bell peppers add a bit of crunch. One serving of egg salad made with two egg whites, 1/2 ounce of plain, fat-free yogurt and 1/4 stalk of celery has 60 calories, less than 1 gram of carbohydrates and 0.5 grams of fat.
The Amazing Inventions of Heron of Alexandria. Heron, also known as Heron of Alexandria, developed many machines and mechanical devices with practical uses, showing that it was possible to take theory and put it into practice. Some of his devices were: 1  A coin operated 'Holy Water Dispenser'. 2  A water organ. 3  The Aeolipile, a steam-powered device.
They invented many things to make their life more comfortable. CALENDAR: The ancient Egyptians created a calendar based on the farming season. There were 3 seasons-the flooding season, the planting season, and the harvest season. Each season was 3 months long. That added up to 360 days. The ancient Egyptians noticed they needed a few more days to fit the seasons. So they added 5 days, holy days, to thank the gods. So thousands of years ago, the ancient Egyptians invented a calendar with 365 days!