A New Speculative Heyday: The “Roaring ‘20s”
The decade following the Great War offered unprecedented opportunities for legitimate entrepreneurs and financial interests, but it was also an era of wheeling and dealing, of risky investments motivated by visions of fortune-making. For the Millars and W. L. Wilder, the postwar enthusiasm seemed at first an open door to success.
Their initial inspiration came from renewed activity on the southeast slope of the diamond field. In late 1919 Reyburn’s dormant venture got an infusion of capital, and in early 1920 built the largest processing plant of the era, a $125,000 facility designed to handle up to 300 loads daily. In 1920-1922 the Arkansas Diamond Company undertook a massive sampling of both the surface layer and the peridotite matrix.
By July 1921, the Kimberlite group felt confident enough to project a budget of $25,000 for the coming fiscal year, even while carrying several thousand dollars of old debt. Austin Millar and close associates coaxed more money from sources in Chicago— including a few trustees and shareholders who had begun doubting the feasibility of mining the Ozark, but were willing to take some risk after hearing that “large financial interests are now associated with the development of the adjoining mine.” For the first time, the shareholders agreed to pay Howard Millar a modest salary. A small group pledged to cover the budget. Records indicate loans of at least $11,500 before July 30, 1922.
Still wary, the group of three investors providing most of those loans required considerable collateral. The Millars and other company trustees deposited $50,000 of their stock and a note for $25,000, at 7% interest, with the collateral trustee. Basically, the lenders were willing to take limited risk for apparent chances at a lucrative sale of the Kimberlite Company‘s property.
In this situation, the Millars dispensed with the previous subtleties of promotion. In the ‘20s, no matter whom they dealt with, the story was simple and straightforward: before the fires in early 1919, they had tested the pure matrix of the Ozark property and gotten an average yield of about 10 carats per 100 loads, with some samplings running well over that. They had proved the Ozark an excellent “commercial” prospect. “At the present market value of diamonds,” Howard told a potential investor in London, “it is conclusive that our mine, when operated on the scale outlined [in a suggested plan for full-scale operation] will yield handsome profits.”
 Supra, “The ADC, 1919-1930.”
 Financing agreement of trustees and major shareholders, for Chicago conference of July 30, 1921, p. 6 (no title or date), V.B.9; report on Chicago conference of Kimberlite Company trustees and major shareholders on July 30, 1921, ibid.
 As expressed in the financing agreement, p. 3. This theme was employed at the Chicago conference, as well. Essentially, the Millars invoked the ADC’s large investment and well-publicized activity on the southeast slope as evidence of the general feasibility of diamond mining.
 Financing agreement of trustees and major shareholders, 6 (Howard Millar’s salary); updated report on Chicago conference, 6-7.
 Ibid., 6.
 Financing agreement of trustees and major shareholders, for Chicago conference of July 30, 1921, V.B.9; updated report, 6-7, ibid. If company trustees defaulted on the note, the collateral trustee would sell stock and diamonds for lenders’ recovery.
 Howard Millar to Wm. De B. Whyte, London, August 17, 1922, with five-page “Results to be Expected” attached, I.N. The primary document is the eight-page report on the Chicago conference of Kimberlite Company trustees and major shareholders on July 30, 1921, with the updated reports covering the period to July 30, 1922 (no title or date, V.B.9). For a later example, Wilder L. Wilder to Bennett C. Clark, St. Louis, August 17, 1926, I.W, referring to the Kimberlite group’s “careful tests after spending $200,000 on the Ozark, showing that the mine is a commercial mine producing 11 carats per 100 loads of 16 cubic feet each.” Apparently, the New York Times relied upon a mixture of Millar’s and Fuller’s statistics in “Diamond Mines are Busy in Arkansas,” June 14, 1931, Sec. 8, 7: diamonds were plentiful enough “to have kept three mining companies busy and to assure them of 21 karats [sic] of rough diamond . . . for every load of thirty-six cubic feet of ore dug up by the men in overalls” (the full-size tram cars used in the 1920s could hold eighteen cubic feet each).
Consequences of the Millar’s earlier promotion were emerging by the mid 1920s. In one instance, the Kimberlite Company received an inquiry from J. Francis Booraem, New York, an industrial engineer representing the estate of J.V.V Booraem, a stockholder. “I am a little surprised” he said, “to note that Mr. Booraem’s investment at the time was made in the Organization as merely a Testing Organization and not one that had really started in actual recovery work.” The writer asked for names of company officers and other information. There were other inquiries from old stockholders at the time (See “Correspondence,” March-June 1924, I.N).