According to the narrator, "The number of souls in this kingdom being usually reckoned one million and a half, of these I calculate there may be about two hundred thousand couple whose wives are breeders, from which number I subtract thirty thousand couple, who are able to maintain their own children, (although I apprehend there cannot be so many, under the present distresses of the kingdom) but this being granted, thiere will remain an hundred seventy thousand breeders. I again subtract fifty thousand, for those women who miscarry, or whose childdren die by accident or disease within the year. There only remain an hundred and twenty thousand children of poor parents annually born. The question therefore is, How this number shall be reared, and provided for." Explain the narrator's metaphor and ironic math?