Soap Bubbles, Chapter 16

          QUESTION BOX. These were the words printed on a box that was standing on Miss Dean’s desk the next morning when the class entered the room.
          Miss Dean said:
          “Those who have questions to ask about scourers may write them now and put them in the question box.”
          Pencils were busy for the next few minutes, for everyone seemed to have at least one question. When the time came to talk about scourers, Miss Dean took the questions from the box and read them to the class. Some she wrote on the board, and here they are:

          Why are abrasives sometimes fine and sometimes coarse?
          Where do the abrasives come from?
          Did the scourer in my tooth paste live in the ocean?
          (Miss Dean smiled at Mary. “I haven’t forgotten your questions,” she said.)
          What else is in scourers besides abrasive and soap?
          How can we tell at home which will not scratch?
          Which is good for the nickel on dad’s car?
          Which will take the rust from my knife?
          What are the coarse abrasives good for?

          ”Please come to the table,” said Miss Dean, “and we’ll see how many of these questions we can answer.”
          She picked up two flat pieces of glass such as she had used in the microscope.
          “One of the most important questions on our list is that which asks how we can tell at home which of these abrasives will not scratch. So let us answer that first.
          “What am I putting between these two pieces of glass?” asked Miss Dean.
          “Some tooth powder.”
          “And between these two pieces?” asked Miss Dean, as she shook some powder between two more glass slides.
          “One of the powders for general use.”
          “Listen while I rub each two pieces of glass together, and so rub the powder between the glass. Is there any difference in sound?”
          “Yes; the tooth powder does not make any sound, but the other has a scratchy sound.”
          “Try this test yourself and notice whether you can feel a difference as well as hear it.”
          “Yes, we can; the tooth powder feels smooth between the glass and the other feels gritty, as though coarse pieces of hard material were in it.”
          “What could you use at home for little glass slides like these?”
          “We could take pieces of window glass or picture glass.”
          “Then when we wish to try a scourer at home, to learn whether it is scratchy for fine surfaces, this is one way to tell , is it not?
          “But we must all have some practice in doing this,” went on Miss Dean. “You have compared a very fine powder with a very coarse one; now take the rest of your scourers and compare them, until you can sort them as fine, medium, and coarse.”
          This was a very interesting thing to do, the children thought, and they set to work earnestly to compare and decide.
          They found sometimes that it was not easy to decide between two kinds of powders:
          “Which of these two seems coarser, Mary?”
          Or, “I think this one is finer than that one, don’t you, George?”
          And, “Jimmy, do you think this one is a bit scratchy?”
          So they helped each other, and when the testing was finished, Miss Dean thought they had made a good division between fine, medium, and coarse scourers.
          “If we say,” said she, “that we may take the finest of these fine scourers for polishing smooth surfaces which must not be scratched, what are some of the things which we might polish with them?”
          “Silver.”
          “Nickel on automobiles.”
          “Where do you find nickel in your homes?”
          After some help from Miss Dean, the children decided that nickel was often found in their houses on faucets, toasters, and chafing dishes, and for the trimming of the kitchen range, and sometimes for bathroom fittings.
          “How about smooth, glossy, painted woodwork,” asked Miss Dean; “should that be scratched and makde to look dull when finger prints have to be scrubbed off?”
          “No, Miss Dean, and mother says the porcelain sink and tiling and bathtub should not be scratched either,” said Jimmy.
          “Many of the scourers in this group of fine abrasives will not hurt painted woodwork and porcelain,” said Miss Dean, “but a bright, smooth surface such as silver has needs very careful polishing.
          “What about these abrasives which are neither coarse nor fine, but medium, and which will scour a little harder than the fine ones?” asked Miss Dean. “You remember that some of these looked like thin pieces of glass under the microscope, and some were mostly rounded in shape, but coarser than the tiny round bits in the silver polishes. Would there be a need for these in our homes?”
          “I know,” said Jimmy, “because I scoured our pots and pans with that kind of scourer. Sometimes Sue let something burn a little and it would stick to the saucepan so hard that if I hadn’t used one of those scourers that food would be stuck to that pan yet.”
          “Do you think your mother would like to use such a pan for cooking?” asked Miss Dean.
          “Well, I guess not,” said Jimmy. “She likes the pots and pans she uses for cooking to shine so you can see your face in them, and she says then she knows they are clean enough for the Martin family to have their food cooked in. So I polished pans every day with these scourers.”
          “Is there any use for these coarsest scourers?” asked George.
          “Yes, many uses, but not so many in our homes nowadays as for the finer kinds,” said Miss Dean, “because we do not use so much iron and steel for our cooking vessels as the people did in olden times. These coarse scourers are good for steel knives and iron pots and frying pans. You might tyr one of these one that rusty knife of yours, George.”
          “But what did the people do for scourers in olden times,” went on Miss Dean, “before they could buy them in the stores?”
          “They had plenty of sand,” said thoughtful John, “and they made soap. So couldn’t they mix their soap with some sand and use that?”
          “Fine,” said Miss Dean, “and that is just what they did. This package of scouring soap and these coarser powders are very much like the soap and sand scourers of those days. Fine white sand on the beaches was much liked for scouring, and people used to take it home in pails to make their scouring soap. I suppose our scourers of these days all grew out of the soap-and-sand scourer of those days, but what would our great-great-grandmothers have thought of the number of different kinds that we have today?
          “Now, children,” Miss Dean went on, “here are silver and nickel and copper which you have brought in, and I have added some steel knives and some saucepans. Here also are some soft cloths. Each one of you will wish to polish something. Choose the scourer you think is right, then dampen one of these cloths, shake or scrape a little of the scourer on it, and rub it over the surface of your article until it is bright and shining. If you wish to look around the room you will probably see some woodwork or some metal which needs cleaning with one of these scourers. Small articles may be rinsed in this hot water after polishing, and woodwork may be wiped with a clean damp cloth. The last step is to take a clean dry cloth and rub your article dry.”
          After her pupils had had a few minutes of busy work, Miss Dean said:
          “Let us put our finished articles on the table and judge them. How does the surface look? Are there any scratches? Is it polished enough to suit you? Did everyone choose the right scourer?
          “I think you have all done a good piece of work,” said Miss Dean, after the children had compared their results and talked about them. “Our time is up for today, and we haven’t answered that question of Mary’s, nor found out anything else which may be in these scourers. So shall we have another talk?”
          “Yes, please, Miss Dean.”
          “Very well,” said Miss Dean, “then I am going to ask each row in the room to be a group to find out all you can about certain words I shall write on the board. You will find that the words have something to do with abrasives. Each group may choose a captain who will report for the group. We will have two days for this. You will find books and magazines on this table later today, in which something about each word will be found, and I have marked the parts which you will need to read. The words are