Unit Four Techniques for Remembering What You Read
Lesson 11 Increasing Your Attention Span
The focus of this lesson is systematic scanning— moving your eyes quickly down the page looking only for specific information. Scanning is also important when it comes to dealing with directories, schedules, manuals, forms, charts, and other English texts.
it reads 1 o’clock. This means that there is one hour’s difference in time between our longitude and that of Greenwich. As we mentioned earlier, this corresponds to exactly 15 degrees of longitude, so our longitude must be 15 degrees west. The world is divided into 24 time zones, and each zone corresponds to 15 degrees of longitude. New York is approximately 5 time zones west of Greenwich, so the time difference must be about 5 hours. By maintaining chronometers on Greenwich time, ships can determine their longitude on any sunny day by merely noting the difference in hours between Greenwich time and local sun time and multiplying this difference by 15 degrees.
Since the sun appears to travel around the earth in 24 hours, it will move 360/24 or 15 degrees in one hour. This reasoning can be used by navigators to determine their longitude. Imagine that we have set sail from Greenwich, England, after having set a very accurate clock, or chronometer, to the local Greenwich time. As we travel westward toward New York, we notice that the sun is going “slower” than our chronometer. At the time that our timepiece reads 12 o’clock, the sun has not quite reached the zenith. As a matter of fact, when our clock reads noon, what it really means is that it’s noon in Greenwich, England. Our clock continues to tell us the time, not at our present location, but at Greenwich. Let us wait until the sun is directly overhead (noon at our location) and then read the time on our clock. Suppose
Form Specific Questions
Scanning is effective only if you have a purpose, so try to fix in your mind what you are looking for by forming specific questions about the topic. Anticipatห้องสมุดไป่ตู้ Word Clues
To get an idea of our location, therefore, we need to know the local time, Greenwich time, and the angle between Polaris and the horizon. 1. In order to get the precise location of a ship, the navigator must know__________. A. his latitude B. both his latitude and longitude C. local time
Identify Likely Answer Locations
Using what you have learned from checking how material is organized, try to identify likely places where the information you are looking for might appear.
HOW TO SCAN
The key to effective scanning is to approach the material in a systematic manner. The following steps provide a systematic approach.
Check the Organization Before you begin to scan, check to see how the article or material is organized. For graphics (maps, tables, graphs, charts, diagrams), this step is especially important. The title of the item you are scanning and other labels, keys, and legends are important to notice. They state what the graphics are intended to describe and tell you how it is presented. For prose selections, assessing the organization is very similar to pre-reading. Your purpose should be to notice the overall structure of the article so that you will be able to predict where in the article you can expect to find the information you are looking for. Headings are especially important to notice since they clearly show how a selection is divided into subtopics.
The next step is to anticipate clues that may help you locate the answer more rapidly. For example, if you were trying to locate the population of New York City in an article on the populations of cities, you might expect the answer to appear in digits such as 2 304 710, or in words such as “two million” or three million.
Of course, longitude gives only half of the information needed to determine our precise location. We must also know our latitude, which tells us how far we are north or south of the Equator. The Equator is the zero line for the measurement of latitude. Circles are drawn parallel to the Equator to indicate other values of latitude. There are 90 degrees of south latitude.
In the Northern Hemisphere, there is a star called Polaris almost directly over the North Pole. This makes it possible to determine the latitude of a given point by setting our sextant to measure the angle between Polaris, the North Star, and the horizon. Mathematicians tell us that this angle is equal to the latitude at the point in question.