23. Explain what is meant by rich lime, poor lime, stone lime.
Which will carry the most sand, and why ? (12.)
*24. Diagram of a loaded truss.
Draw, to double the size, omitting as many members as possible, and marking with a x all the remaining members brought into compression by the load. (14.) *25. Plan of a fireplace in a ground-floor room.
Draw, to a scale of 1/24, a section through A - A, showing all the detail of the construction. (14.)
Show, to a scale of ¾" to a foot, the arrangement of the bricks in two successive courses. (14.)
Under what circumstances would the latter joint be used ? (16.) 28. Give a part elevation and a cross section of a plate girder 2 feet deep, with a ¼" web, connected to flanges, each consisting of two 12" x 3/8" plates ; the rivets to be ¾" diameter, with a pitch of 4". (16.)
29. Draw, to a scale of 3 feet to an inch, an elevation of about half of a wooden roof truss for a 34 feet span, containing the following members: - Tie-beam, 10" x 5". Queen posts, 5" x 3½". Principals, 5" x 5". Straining beam, 5" x 6".
Braces, 4" x 2½". (16.)
*30. Vertical section through the base of the outer wall of a brick dwelling-house built on a damp site.
Draw, to a scale of ½" to a foot, showing the joints of the brickwork, and making any alterations or additions you consider necessary to prevent the damp from affecting the walls. (17.)
31. Give a cross section, to a scale of 1" to a foot, through the ridge of a slated roof, showing three courses of Duchess slates centre nailed on 3" x 1" battens, with 4" x 2" rafters, and a 9" x 1 ½ ridge-piece finished with slate ridging.
Also give a similar section showing the details of a lead ridge roll.
Draw, to a scale of ¾" to a foot, the outside elevation ; also a section through A - A, to double the scale. (18.)