As in redrawing a die the engravers of the Nesbitt envelopes have endeavored merely to reproduce the stamp in its general features, the result is that the spacings between the letters, the form of the letters, their size, and the size of the entire stamp may all be subject to many changes. Owing to this nonchalant procedure, and referring now to the very first issue, the engravers have left to posterity not less than ten different heads of the "Father of our Country" which can readily be seen on fine specimens. For the same reason there are ten dies of the 3 cent red, commonly known as Die 5 or E, which are further characterized by the "T" of "THREE" having a long cross stroke. This die was redrawn and the long cross stroke of "T" changed into a short line. The alteration added twenty varieties, among which are some highly interesting and valuable specimens. Suppose we select the "T" of "THREE" for our starting point and, noting that that letter is found in various positions, slanting to the right or left, or standing nearly vertically, we lay the edge of a fine piece of paper along the outside of the downstroke and thus virtually prolong the "T" line downward. Next we carefully note where that prolongation touches a letter in the lower label. If we find that in a number of dies the line touches the "N" of "CENTS", we have probably established a general class. Continuing our inquiry we may note that the "T" line falls outside of the "N", perhaps touches the "T" or may even cut the "S" of "CENTS"; a clear indication that we have other die varieties. The above, I believe, illustrates sufficiently what is meant by a system of line prolongation. Another great help is furnished by the use of a uniform distance measurement. For convenience take ten millimetres and, setting a divider at that distance, commence with the "T" of "THREE", selecting as our starting point the left end of the horizontal cross stroke of "T". Assume that, in our first specimen, the end of the ten millimetre line touches the end of the first "E", in the second it may fall between the two "E"s, while in a third the same distance reaches outside the final "E". In this simple and comparatively easy manner, we have ascertained three important classes. Knowing our main classes, the next step is to study a number of dies of the same general class for sub-varieties, using again one or both of the methods with which we are now well acquainted. In this manner order is brought out of apparent confusion, and if we work carefully, and are willing to have a little patience, the final success will pay well for all our trouble. Indeed the mental training gained by this work is very valuable and will assist us greatly in the knowledge of other stamps or dies.