Percy first worked out the data for the Miami black clay loam.  The chemist had analyzed the soil separates for only four constituents, and they showed the following amounts per acre of plowed soil to a depth of six and two-thirds inches, averaging two million pounds in weight: 

2,970 pounds of phosphorus

38,500 pounds of potassium

18,440 pounds of magnesium

46,200 pounds of calcium

He then made the computations for the average of the Leonardtown loam of St. Mary County, Maryland, with results as follows: 

160 pounds of phosphorus

18,500 pounds of potassium

3,480 pounds of magnesium

1,000 pounds of calcium

Percy stared at these figures when he brought them together for comparison.  He then checked up his computations to be sure they were right.

“Almost twenty times as much phosphorus!” he said to himself.  “Is it possible?  And more than forty times as much calcium!  Let me see!  It takes one hundred and seventeen pounds of calcium for four tons of clover hay.  The total amount in the plowed soil of the Leonardtown loam would not be sufficient for eight such crops; and six crops of corn such as we raised one year on our sixteen acres would take more phosphorus from the land than is now left in the plowed soil of this Leonardtown loam.  The magnesium is not quite so bad—­about one-fifth as much as in our black soil, and the potassium is almost one-half as much as we have.”

Percy next turned to the Porters black loam, which he had noticed was to be found not many miles from Montplain.  He thought he might induce Mr. West to drive with him to the upper mountain slope in order that they might see that land.  His computations for the Porters black loam gave the following results: 

4,630 pounds of phosphorus

48,300 pounds of potassium

12,360 pounds of magnesium

23,700 pounds of calcium

He viewed these figures a moment with evident satisfaction.

“Plenty of everything in this wonderful ‘pippin land,’” he thought.  “Big yields reported for everything suited to that altitude.  ’Can be worked year after year without apparent impairment of its fertility,’ so the Report stated.  I should think it might, especially since clover is one of the crops grown.  Both phosphorus and potassium are way above our best black land.  Magnesium two-thirds and calcium one-half of our flat land, but still greater than our common prairie, according to the average they gave us at college.  And no doubt there is plenty of magnesian limestone in these mountains which could be had if ever needed.  The soil surveyor certainly did not say too much in praise of the Porters black loam, considering that its physical composition is also all right.”

He worked out the Norfolk loam to see what he would get if he accepted Miss Russell’s dare.  The following are the figures: