Land Cruising - Prospecting:
Introduction To Land Cruising
Land Cruising And Prospecting
Examining And Locating
Points For Homesteaders
Prospecting For Gold, Etc.
How To Locate A Claim
Read More Articles About: Land Cruising - Prospecting
( Originally Published Early 1900's )
The compass is the "whole thing" in looking up land or locating a mineral claim. Without this little instrument we could do absolutely nothing. It is simple but very sensitive. It is no more than a sharp steel post on which is pivoted a flat steel needle which is magnetized. This needle swings over a dial made of brass or enamel and it will always point north and south no matter how much you scrap with it and say it is wrong.
One end of the needle is colored blue and this blue end always points north and for very strong reasons it is a good plan to take the sharp point of your pocket-knife and scratch on the bottom of your compass "Blue points North." I will have more to say on this subject later under head. of "getting lost."
It is not necessary to pay a big price for a compass, a fairly good one can be bought for $8.50 to $16.00. The small pocket compasses are useless to survey land with, although they are all right for what they are intended, to work your way out of the woods in case you are lost, but for running long accurate lines they are not intended. The writer of this book has brought out a compass which is a modification of the U. S. A. Cavalry Scouts Compass, is very light and compact and strong. Long accurate lines can be run with it and the inventor hopes to be able to sell it for about $3.00.
The average compass bought from a store dealing in them should have a jewel mounted needle not less than 1 3/4 inches long and an enameled or brass dial with eight graduations, N-E-S and W, also NE-SW and NW and SE. The compass must be equipped with good simple sights; it should always be level, when taking a sight care being taken not to let either end of the needle touch the glass.
It should be carried in a good harness leather case with a strap to hang over the shoulder and incidentally always hang any compass up, don't lay it on the ground either in the field or in camp. When taking a sight don't have any guns, axes or other iron or steel close to it. It is a good plan to have your harness leather sheath made large enough to carry your note book in, in order to keep it dry.
In addition to your large compass it is well to carry a small, cheap pocket compass so if anything happens to your large compass you can find your way out with the small one. Don't let your compass get wet. If it shows damp under the glass, dry it out as it is useless if wet or damp. Dry it with a gentle heat for if it gets too hot it destroys the magnetism in the needle.
Now the needle of the compass seldom or never points to the true north and south. On the Pacific Coast the needle will swing to the east of true north and on the Atlantic Coast it will swing west of the true north. This is called the magnetic variation. The true north is called the true meridian and this true meridian must be found before you start work on any job of surveying, and in the same locality that you are going to run your lines.
This true meridian is found by the sun, also by the north or polar star. If you have a good watch, which every cruiser or prospector should have, and it is set right, this is easily done. Thus on a level, clean bit of ground, find the north by your compass and lean a pole toward the north resting it in a crotch made of two sticks as shown in the cut.. Suspend a weight from the end of the pole so it nearly touches the ground. Then at 11 a. m. attach a string to a peg driven directly under the weight and with a sharpened stick attached to the other end of the string, describe an arc of a circle with a radius equal to the distance from the peg to the shadow of the tip of the pole.
Now drive a peg on the arc of the circle where the shadow of the tip of the pole rested. About 1 p. m. watch the shadow of the tip of the pole as it approaches the eastern side of the arc and drive another peg at the point where it crosses the arc. Then by means of a tape line, stick or string, find the middle point of the straight line joining the last two pegs mentioned. A straight line joining this middle point and the peg. under the weight will be the true north and south. On a true meridian if a distant object, such as a pole be placed so as to prolong this line one has only to go to it and sight his compass back on the tip of his incline pole in order to get the variation of the compass needle from the true meridian or true north. The needle may be a few degrees east or west of your line of sight but whatever it is a note must be made of it and use this variation when running a line in this district.
The above cut shows how to take the true north and south by the sun. The true north and south can also be found by the north or polar star at night. It is a fairly bright star and is nearly in line with the two stars that form the side of the dipper farthest from the handle and looking from the bottom of the dipper. When these two stars are in line either above or below the north star, hang two lines with weights attached in line with the north star and the two stars above mentioned. The lines should be twelve or fifteen feet apart and a light of some kind will have to be used. This line can be prolonged by daylight and your compass sighted and the variation noted.
The above cut shows north star, also the big dipper and the relation of the lines to the stars in the dipper.