OUR readers have noticed, perhaps, a slight change in size. We found, soon after our enlargement, two years ago, that our size was then one half inch too long, and one half inch too wide for previous volumes of the series, and at the end of the year 1869, in binding, we discovered that the margin had to be trimmed down so close to make the height uniform, that it displayed the border around the reading matter in an awkward shape. As soon as our paper supply was exhausted, we determined upon a change, and have just adopted it with our January number. We have left off the old border, reduced the size to correspond with the earlier volumes of the series (from 1850 to 1860), and yet we have not ourtailed our reading matter. Our readers will find, by measurement, that we give precisely as much reading matter now as last year, while the $300 per annum formerly spent in maintaining a useless border and extra margin, we shall hereafter devote to increasing our fund of illustrations, together with a better quality of paper, and other improvements.