to the nail-head, and the vertical angle read to the same point, thus enabling the horizontal distance to be calculated.

The readings are made to hundredths of a foot. Some surveyors measure back and forward from each station as a check, but this is hardly necessary with careful work.

The distance between stations is limited by the contour of the country and the length of the tape. With a tape of the ordinary length the distance between stations would be less than 500 ft.

In making a measurement care should be taken that the tape is straight and subjected to a pull depending on the distance that the tape is unsupported. Then get the point on the tape opposite the axis of the instrument, and with the small tape measure along from this point toward the zero end of the long tape to the nearest graduation. This will give the number of feet and fractions to be added to the reading at the graduation mark, and the sum is recorded as the slope distance.

Field-work and Adjustment of Claim.-The field-work is generally accomplished with the aid of one assistant, who carries the forward end of the tape, puts in stations, clears out the lines, assists in setting corners, etc. In a heavily timbered country an extra axeman is of advantage. The field-work consists in the determination of the true meridian by astronomical observation, as explained in Chapter XIV, finding the position of the corners of the location survey, the discovery shaft, and all improvements on the claim, whether made by the claimant or not. The corners of conflicting prior official surveys must be located, and a tie made to a corner of the Government land survey, if one exists within two miles, or, if such does not exist, the tie is taken to a U. S. L. monument as described in the Manual of Instructions for the Survey of the Mineral Lands of the U. S. prepared by the Commissioner of the General Land Office. This work will be alluded to hereafter as the Manual

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of Instructions. It is reprinted in full in Appendix B and must be studied in connection with all that is written here in regard to patent work.

Before the deputy can have official authority to survey the claim the applicant must send his application for an order for the survey, accompanied by a certified copy of the "location certificate," to the Surveyor-General, and deposit the required fees (see Manual of Instructions). The Surveyor-General will then issue to the surveyor mentioned an order for survey, designating the survey number to be used. A copy of the certified copy of the location certificate is also enclosed.

It is well, however, to tie up the claim before the claimant makes application for the survey order, and, if the location does not agree with the description given in the location certificate, to make out and file an amended certificate giving the correct description. This may save some time and a little expense. The Land Office at the present time is very particular and will allow but slight variation between the field-notes turned in by the deputy and the location certificate on which the order for survey was based.

The next step, after tieing up the claim, is to compute or adjust the lines of the final claim to be used in the application for the patent.

The conditions are imposed by the fundamental principle that monuments hold over descriptions and by the law and Land Office regulations on this subject. These conditions are summarized as follows:

1. The final claim must lie wholly within the location stakes.

2. The length along the vein or lode must not exceed 1500 ft.

3. The end lines must be parallel.

4. The distance from lode line to side line must at no point exceed half of the statutory width.

5. The lode line must pass through the discovery shaft. 6. The end lines must be free, as explained in the Manual of Instructions.

7. The bearings must be given from the true meridian.

Having the lines of the final claim computed in accordance with the above, the patent corners are set as described in the Manual of Instructions.

The meridian used should never vary more than 2 or 3 minutes from the true meridian. If the variation with some conflicting survey is more than this, these surveys must be reported as disagreeing, as provided in the Manual of Instructions.

It is now the common practice of deputies to find the meridian by direct solar observation, as explained in Art. 103a, although some still use one of the various solar attachments.

Below is given an actual example of the notes, etc., of the Jewel lode in the Cripple Creek Mining District in Colorado. This was selected as a typical example from a large number of surveys with which the writers have been connected both in this and other districts. The survey was made with a light mountain transit and a 500-ft. tape, etc., as described. The field-work included the following operations: The true meridian was determined by direct observation, the image of the sun being thrown on a card held behind the eyepiece. Two symmetrical sets of sun observations were taken, one before and one after noon. A traverse was run to tie up the location corners of the Jewel lode, and also the corners of patent surveys, Nos. 9689, 8882, 9134, 9122, 9190, 8927, the improvements, and a corner of the Government survey. In this case the order for survey had been received by the deputy, 10264 being the survey number assigned.

The notes as actually taken in the field are shown on p. 361. The first section of the notes taken on Jan. 20 represent the ticing-up survey, as it is called. When this was finished, the

407

320° 44' 321° 7'

+ 21° 00'

9.35 A.M.

115.97

4/9689.

356°

90° 01'

90° 28'

358°

301.60

265.39

30'

0:00:0

3580

57′

402.20
129.58

358° 358°

319° 23'

358° 57'

316.55

4°

55'

50'

321.95
283.20

134° 42'

185.00
210.50

level

Shaft 5 X 7 X 13.

4 X 6 X 12.

4/9134.

1/4 cor.

notes were taken to the office, where the slope distances were reduced to the horizontal, the sun observations calculated, and the true meridian determined. The corrected azimuths were inserted in column 3 of the notes, and the horizontal distances in column 6 as shown. The work was also platted as shown by Fig. 90, the transit lines as run in the field being dotted and the claim lines shown unbroken. The bearing and lengths of the lines of the claim were calculated from the data obtained from the notes. It will be seen by Fig. 90 that the north end of the Jewel lode was taken in by Survey No. 9190, Ida, No. 1 lode, a patent claim of prior location. This necessitated the cutting back of the Jewel lode until it had a free end centre off the Ida No. I lode (as shown in Manual of Instructions). Calculations were made from which to set the patent corners to conform with the above requirement. A traverse was calculated from Station I to Corner No. 1.

The notes of Feb. 6, p. 361, show the work of setting the corners, Fig. 91. Cor. No. I was set from Station 1, and Cor. No. 4 was set from Cor. No. I. Cor. No. 2 was identical with the S.E. corner of the location, and Cor. No. 3 was set from it.

The method of measuring a given distance on sloping ground is best done in the following way: Set a point on line within a foot or two of the given distance, measure the vertical angle and calculate the horizontal distance. The remaining small distance is measured either backward or forward hori zontally to the required point.

The style and markings of the corners are described in the Manual of Instructions. With a stone corner the exact point is marked by a cross chiselled into the stone. Post corners are preferably more than 4 inches square, the exact point being marked by a nail driven in.

In making the calculations a seven-place table of logarithms. is largely used, although a six-place table would serve.

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