Yet the more the three pondered over the matter the greater became the puzzle.  The notes of the surveyor, Matt Rice, and of the leveler, ’Gene Black, were at utter variance.

“We must get hold of these men as soon as they come in tonight,” exclaimed Mr. Thurston, much disturbed.  “We must find out just which one is at fault.”

“Rice is a very reliable man, sir,” spoke up Tom.

“Yes; but Blaisdell reports that Black thoroughly understands his work, too,” grumbled the chief.  “We must settle this tonight.”

“May I make a suggestion, sir?” asked Tom.

“Certainly.  Go ahead.”

“There is no use, sir, in my going ahead with this profile drawing, if there’s a chance that the sights turned in by Black are wrong.  Until we know, my time at this drawing board may all be wasted.  Trotter, one of the rodmen, is in camp today.  I might take him, and a level along, and go over the foresights and backsights myself.  All of the stakes will be in place.  In two hours I ought to have a very good set of leveling notes.  Then I can bring them back and compare them with Black’s sights.”

“Can you run a level well?” inquired Mr. Thurston.

“Of course I can, sir.  It’s simple enough work, and I’ve done a good bit of it in the east.”

“Go along, then, and see if you can throw any light on this,” sighed the disturbed chief.

“Reade really ought to have two rodmen,” broke in Harry eagerly.  “May I go along, sir, to serve as the other rodman?”

“Run along,” assented Mr. Thurston.  “Remember, boys, I can’t go any further until this tangle is settled.  Come back as speedily as you can.”

Tom and Harry snatched up their sombreros, hurrying forth.  Trotter was found readily, and was ordered to saddle three ponies.  Tom busied himself in picking out the best leveling instrument in camp, while Hazelton secured the rods and a chain.  Then the party set forth in Indian file, Tom riding in advance.

A trot of half an hour brought them to Section Nineteen.  Here Tom speedily adjusted his instrument, taking up his post over the first stake at the bottom of the hill.

Leveling is not difficult work, though it calls for some judgment and a good deal of care.  For instance, when Tom set his telescope exactly level and took a reading of the rod at the second stake, which Harry held, he read the height as eight feet and four inches.  Then he trudged forward, carrying his instrument, while Trotter held his rod exactly perpendicular over the first stake.  From the second stake Tom sighted back through his telescope, reading two feet three inches.  The difference between these two readings was six feet and one inch, showing that, for the distance between first and second stakes the rise in the hillside was six feet one inch.  Thereupon Reade turned and sighted, from stake number two to stake number three, noting in his book the reading he secured from the rod at number three.  Once at number three he turned his telescope backward, taking a reading from Trotter’s rod at number two.  Ten stakes were thus covered, and not only were the foresights and backsights read and recorded, but the distance between each pair of stakes was measured with the chain and the distances entered on the record.