To these three rules all writers of children's books profess to conform; yet a good book for children is a rarity; for, simple as the rules are, they are very little understood. While all admit that the style should be simple and familiar, some appear to think that anything simple to them will be equally simple to their child-readers, and write as nearly as possible in the style of "The Rambler." Such a book is "The Percy Family," whose author is guilty of an additional impropriety in putting his ponderous sentences into the mouth of a child not ten years old. Another and more numerous class, evidently piquing themselves not a little upon avoiding this error, fall into another by fancying it necessary to _write down_ to their young readers. They explain everything with a tiresome minuteness of detail, although any observer of children ought to know that a child's mind does not want everything explained. They think that simplicity demands this lengthy discussion of every trivial matter. There is such a thing as a conceited simplicity, and there is a technical simplicity, that in its barrenness and insipidity is worthy only of a simpleton. In Jacob Abbott's "Juveniles" especially, by means of this minuteness, a very scanty stock of ideas is made to go a great way. Does simplicity require such trash as this? "The place was known by the name of the Octagon. The reason why it was called by this name was, that the principal sitting-room in the house was built in the form of an octagon, that is, instead of having four sides, as a room usually has, this room had eight sides. An octagon is a figure of eight sides. "A figure of four sides is called a square. A figure of five sides is called a pentagon, of six sides a hexagon, of eight sides an octagon. There might be a figure of seven sides, but it would not be very easily made, and it would not be very pretty when it was made, and so it is seldom used or spoken of. But octagons and hexagons are very common, for they are easily made, and they are very regular and symmetrical in form." The object of all this is, doubtless, to impart valuable information. But while such slipshod writing is singularly uninteresting, it may also be censured as inaccurate. Mr. Abbott seems to think all polygons necessarily regular. Any child can make a heptagon at once, notwithstanding Mr. Abbott calls it so difficult. A _regular_ heptagon, indeed, is another matter. Then what does he mean by saying octagons and hexagons are very regular? A regular octagon is regular, though an octagon in general is no more regular than any other figure. But Mr. Abbott continues:--