What is the use of a compass? ( ) A A to set the course of the ship B to measure the position of the ship C to measure the speed of the ship D to tell the time
3 Can you identify these early navigational instruments seamen used and explain how they are used? 1 _co_m__p_a_s_s_(_in__a_n_ci_e_n_t_C_h_i_n_a_)___ 2 _a_s_tr_o_l_a_b_e_ 3 _s_e_x_ta_n_t___ 4 _s_e_a_/_n_a_u_t_ic_a_l_/_m__a_ri_n_e_c_h_a_r_t _
Very often navigators are also explorers.
Pre-reading • Look at the pictures. Then answer the
questions.
1 How do you think seamen found their way before modern accurate methods of navigation were invented?
• Beating circle: _to__c_o_m_p_a_r_e_t_h_e_h_e_i_g_h_t _o_f_th_e__s_u_n_n_o_w____ _w_i_th__t_h_e_p_o_s_it_io_n__o_f_t_h_e_'s_u_n__at__m_i_d_d_ay.
You wanted to keep a straight course.
use a compass
You were lost with no land in sight.
measure your position using the sun or stars; look for sea birds, cloud formations, fog or seaweed to show that land is nearby
Explorer
land use of compass and
landmarks find new places within an
already identified island or continent
Explorer is someone who travels into or through a place in order to learn about it.
2 Why are speed and time important in working out the longitude of a ship?
Speed and time are important in finding out the longitude of a ship because the earth moves fifteen degrees westwards every hour. If you know your direction, speed and time, you can work out the approximate longitude or change in your position in relation to the stars.
3 Why is the position of the sun and various stars useful for working out latitude?
The position of the sun and stars are useful for working out latitude because they are fixed points in the sky and their movements in relation to the earth are already known. So they can be used to measure a ship's position.
What would you do if:
Plan of action
You were far from land and a storm arose.
wait till the storm is over, and then find your new position and return to your original course
4 Read the passage again and use the information to analyse the navigational skills. Write the answers in your own words. Using nature
1 To find the ship's position at sea a sailor used the North Star and the sun.
1 _m_e_a_s_u_r_in_g__ti_m_e__a_n_d_s_p_e_e_d____
2 _c_o_m_p_a_s_s_a_n_d__c_o_m_p_l_ic_a_t_e_d__ __m_a_t_h_em__a_ti_c_a_l_ta_b_l_e_s___ .
5 Write down the working principles of the following instruments:
Kept close to the shore, used nature such as the sun, wind, birds, tide, etc, to help them, and used some of the instruments including a compass, astrolabe, etc.
Navigator sea nautical instruments
find new islands or continents
Navigator is someone who finds the position and plots the course of a ship, an aircraft, a car, etc, using maps and instruments.
You knew your latitude but didn't know your longitude.
use knots to find your speed and work out your approximate longitude
You were blown off-course.
use the compass and the astrolabe, quadrant or sextant to find out your position, return to your former course
2 A sailor knew that land was nearby if he saw _fr_e_s_h_s_e_a_w_e_e_d_,_n_e_s_ti_n_g_b_i_rd_s__re_t_u_rn_i_n_g _h_o_m_e__in__th_e__ev_e_n_i_n_g_o_r__fo_g__ .
新课标人教版课件系列
《高中英语》
选修(模块）9-2.1
In pairs discuss these questions: 1 What is a navigator?
A navigator explores new routes across the sea. 2 What is the difference between a navigator and an explorer?
You were offshore but you needed more food and water.
follow nesting birds to shore; look for special cloud formations or fog used _se_a__c_u_rr_e_n_ts__o_r_ti_d_e_s_a_n_d__w_i_n_ds to increase their speed.
Using instruments 4 There were two methods to find longitude:
2 Which do you think was easier to work out: latitude or longitude?
Latitude, because it was used to measure how far you had travelled from land on a straight line. It was discovered a long time before longitude.
A navigator explores the sea; an explorer discovers new places on land.
3 Look at these famous people. Are they navigators or explorers? What do you know about them?
4 Which ones do you think are still used today? Sea charts are still used today.
Comprehending
1 Read the passage and answer the following questions. 1 What is the use of a bearing circle, astrolabe, quadrant or sextant? ( )B