Calendar: 1877-1878 Page 613

ENGINEERING AND APPLIED SCIENCES 611 one thirds of degree how would you construct vernier to read off to 20 seconds Ρ The variation of the needle being 12 15' what will be the true bearings of the following 68 15' 23 29 82 27 10 50 base line measured on plateau 13 000 feet above the level of the sea was found to be 10 miles long What is its true length at the sea's level Lay out rectangle containing 160 acres in such manner that one side shall be 30 chains longer than the other side When river too broad to be measured by the chain oh- structs your describe the different methods that can be employed first by the chain alone secondly with an angular instrument to ascertain its breadth FIRST YEAR What is the length of "Gunter's chain 1' in feet and why is that particular number taken Describe the circumferentor and how it is used to traverse wood Describe the spirit level and explain what is meant by "backset "foreset "reduced level Β and "datum line When using the theodolite how do you repeat an angle Give an example Describe the theodolite its construction and uses in the field In most theodolites the vernier reads to minutes only How then can you read to seconds When would it be preferable to use the circumferentor instead of the theodolite What is meant by true and magnetic north The periphery of circular field is 76 chains find the contents in acres roods and poles of path 10 feet wide running all round it inside