The castle-building habit，the day-dreaming habit—how it grows！what a luxury it becomes；how we fly to its enchantments at every idle moment，how we revel in them，steep our souls in them，intoxicate ourselves with their beguiling fantasies—oh yes，and how soon and how easily our dram life and our material life become so intermingled and so fused together that we can't quite tell which is which，any more.
By and by Aleck subscribed for a Chicago daily and for the Wall Street Pointer.With an eye single to finance she studied these as diligently all the week as she studied her Bible Sundays.Sally was lost in admiration，to note with what swift and sure strides her genius and judgment developed and expanded in the forecasting and handling of the securities of both the material and spiritual markets.He was proud of her nerve and daring in exploiting worldly stocks，and just as proud of her conservative caution in working her spiritual deals.He noted that she never lost her head in either case；that with a splendid courage she often went short on worldly futures，but heedfully drew the line there—she was always long on the others.Her policy was quite sane and simple，as she explained it to him：what she put into earthly futures was for speculation，what she put into spiritual futures was for investment；she was willing to go into the one on a margin，and take chances，but in the case of the other，“margin her no margins”—she wanted to cash in a hundred cents per dollar's worth，and have the stock transferred on the books.
It took but a very few months to educate Aleck's imagination and Sally's.Each day's training added something to the spread and effectiveness of the two machines.As a consequence，Aleck made imaginary money much faster than at first she had dreamed of making it，and Sally's competency in spending the overflow of it kept pace with the strain put upon it，right along.In the beginning，Aleck had given the coal speculation a twelvemonth in which to materialize，and had been loath to grant that this term might possibly be shortened by nine months.But that was the feeble work，the nursery work，of a financial fancy that had had no teaching，no experience，no practice.These aids soon came，then that nine months vanished，and the imaginary ten-thousand-dollar investment came marching home with three hundred per cent.profit on its back！
It was a great day for the pair of Fosters.They were speechless for joy.Also speechless for another reason：after much watching of the market，Aleck had lately，with fear and trembling，made her first flyer on a “margin，”using the remaining twenty thousand of the bequest in this risk.In her mind's eye she had seen it climb，point by point—always with a chance that the market would break—until at last her anxieties were too great for further endurance—she being new to the margin business and unhardened，as yet—and she gave her imaginary broker an imaginary order by imaginary telegraph to sell.She said forty thousand dollars'profit was enough.The sale was made on the very day that the coal venture had returned with its rich freight.As I have said，the couple were speechless.They sat dazed and blissful that night，trying to realize the immense fact，the overwhelming fact，that they were actually worth a hundred thousand dollars in clean，imaginary cash.Yet so it was.
It was the last time that ever Aleck was afraid of a margin；at least afraid enough to let it break her sleep and pale her cheek to the extent that this first experience in that line had done.
Indeed it was a memorable night.Gradually the realization that they were rich sank securely home into the souls of the pair，then they began to place the money.If we could have looked out through the eyes of these dreamers，we should have seen their tidy little wooden house disappear，and a two-story brick with a cast-iron fence in front of it take its place；we should have seen a three-globed gas-chandelier grow down from the parlor ceiling；we should have seen the homely rag carpet turn to noble Brussels，a dollar and a half a yard；we should have seen the plebeian fireplace vanish away and a recherché，big base-burner with isinglass windows take position and spread awe around.And we should have seen other things，too；among them the buggy，the lap-robe，the stove-pipe hat，and so on.
From that time forth，although the daughters and the neighbors saw only the same old wooden house there，it was a two-story brick to Aleck and Sally；and not a night went by that Aleck did not worry about the imaginary gas-bills，and get for all comfort Sally's reckless retort：“What of it？We can afford it.”
Before the couple went to bed，that first night that they were rich，they had decided that they must celebrate.They must give a party—that was the idea.But how to explain it—to the daughters and the neighbors？They could not expose the fact that they were rich.Sally was willing，even anxious，to do it；but Aleck kept her head and would not allow it.She said that although the money was as good as in，it would be as well to wait until it was actually in.On that policy she took her stand，and would not budge.The great secret must be kept，she said—kept from the daughters and everybody else.
The pair were puzzled.They must celebrate，they were determined to celebrate，but since the secret must be kept，what could they celebrate？No birthdays were due for three months.Tilbury wasn't available，evidently he was going to live forever；what the nation could they celebrate？That was Sally's way of putting it；and he was getting impatient，too，and harassed.But at last he hit it—just by sheer inspiration，as it seemed to him—and all their troubles were gone in a moment；they would celebrate the Discovery of America.A splendid idea！