2) features of the ocean floor; 3) the concept of sea-floor spreading; and. 4) the nature of the Earth's magnetic field and the fact that it has reversed its polarity many times in the past. The Earth's layers â The Earth is a layered planet consisting of crust, mantle and core (Fig. 1).
Run your sprinklers for 15 minutes. Use a ruler to measure the depth of water in each can. Add all the numbers, and then divide by the number of cans to find the average output. This average number is your sprinkler number. It is the average amount of water your sprinklers apply in 15 minutes.
The best time to water is early morning, when the sun starts to rise. You lose some water to evaporation in the middle of the day. And watering at night leaves the grass wet too long, which can cause fungus and other diseases in the summer. Give your lawn 3/8 in. of water three times a week. Calculate the amount of time it takes your sprinkler to dispense that much water (Photo 5). Set a timer (sold at home centers and lawn and garden centers) on your hose spigot so you won't have to watch the clock (Photo 6).