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Geography Paper 1 ,May/June 2009  
Questions:   1 2 3 4 5 6 7 8   Main
General Comments
Weakness/Remedies
Strength






























Question 2

(a) Describe any three of the following survey instruments:
    (i) ranging poles;
    (ii) chain;
    (iii) cross staff;
    (iv) arrows.
(b) Outline the processes involved in carrying out chain survey.
_____________________________________________________________________________________________________
Observation

This was an unpopular question among the candidates. Their performance on the (a ) part of the question was poor. Many of the candidates could not describe the survey instruments properly. Candidates should devote  special attention to the segment on surveying since it is a vital aspects of the  geography curriculum.  Schools should purchase these instruments and put them to practical use. A description of each of the survey instrument is given below:
      Ranging poles:

  • made of light poles of circular section which is between 25 to 30 mm in diameter
  • has iron shoe at one end to allow it to be fixed into the ground
  • the poles are made of light metals or seasoned wood
  • painted in alternate bright colours as white, red and black to make it visible from afar
  • a ranging pole is between 1.8m – 3m in length

    Chain:

  • formed by 100 pieces of wire
  • connected by small links
  • there is brass handle for holding  at the end of the chain
  • the handle forms part of the distance
  • the chain has 10 links
  • the chain can be 66ft or 100ft; 20m or 30m long
  • at every metre of the chain, there is a brass tag or tally to aid reading
  • every 5m and 10m of the chain also carries a different tag for identification

     Cross staff:

  • made of metals
  • the head is mounted on a shortened version of a ranging pole
  • consist of cross with vertical end members
  • each has slits
  • the line of sight is between cross at right angles
  • the arms are turned upwards at the ends

    Arrows:
  • thin painted steel wire
  • has pointed metal markers
  • about 381 mm or 15in long
  • bent at the top into a ring
  • to which red pieces of clothes can be attached to make them more visible
  • painted in bright colours to make them easily visible

     The processes involved in carry out chain surveying are:

  • reconnaissance survey of the area
  • sketch map
  • chain survey requires a surveyor and two assistants
  • surveyor stays at the starting point and a station is fixed
  • a lead chainman is in front while the other holds the chain at the zero end.
  • leader carries arrows and ranging poles
  • with the poles, he aligns the points and moves the chain to line
  • when the chain is steady at the zero point on a station A, the lead chainman fixes an arrow at the end of the chain length
  • the leader then drags the chain towards the target station
  • the distances measured are entered into the field notebook
  • offsets are indicated
  • The measured distances and offsets are plotted.

 

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