ANSWEES.

Otago Witness, Issue 1324, 14 April 1877, Page 13

ANSWEES.

MR AUTHUR BEVERLY sends the following answers to fra geodetic questions :~ ' '. , .Centre to junction ... 19-.023 miles \ - Pe/p. on vertical 13246 . do Length of radius':.. ... 3956-052 :do " J. MITCHELL, Dunedin, writes:—"ln last Saturday's issue of the Witness, Mr A. Beverly asks a solution of ttie following queries: —'If the equatorial diameter of the earth be 79257 miles, and the Polar-diameter 26| miles less, what'is the radius of the earth at' Dunedin; and at what distance from"the earth's centre will'the vertical line meet'the .axis ?' To the firsfc I answer. 3956 l miles. To the r second 19 miles north of the centre;' or'thereabout.- I may he allowed to say that' this'difference of diameter is too great according to modern acceptation, consequently, the .deflection, of the vertical line from a true . radial'line of the'earth comes outtoo 'great, '• . and therefore the above distance (19 miles) too * ;. great. According to the generally received' Tolar compression (about sfo), the angle of • the vertical at Dunedin is li\l6"-4, and there- r fore 1 ought to-meet the earth's axis at about 18.63 miles onlyfronvthe centre. t It is simply, : a question of/ .'given two angles .(U'-i6" and 90°+thegeo-centriclafcitude) with the included - side (the earth's, radius), to find the sideJ. L., Dunedin, writes "My plan for preventing! that colt front doubling in his feet would .he to shoot him." ,1^ , HiJ.S., Invercargill.—The rule by which you solve No. 236 13' quite correct, assuming a pound to be the unit or integer. • It is called, cross multiplication,: and is used chiefly in timber measurement. A simple rule is to "reduce the given amount to a decimal', square,' and .then reduce, .back to the original denominations. (j, , , f