«A» The lower part is essentially bigger, and the cross-bar is not raised, as that would make the top part disproportionately small.
«F» usually follows E, but being asymmetrical and open below it may, if desired, be made with the bar at--or even slightly below--the actual centre.
«R» In early forms the bow was frequently rather large (see Plate II.), but it is safer to make the tail--the characteristic part--more pronounced (see Plates III., XXIV.).
«P» The characteristic part of P is the bow, which may therefore be a little larger than the bow of R (see Plate III.).
«S» In the best types of this letter the upper and lower parts are approximately equal; there is a tendency slightly to enlarge the lower [p275] part. (In Uncial and early round-hands the _top_ part was larger: see Plates IV. to VII.)
Y varies: the upper part may be less than that of X, or somewhat larger.
_The essential or structural forms_ (see p. 240) _are the simplest forms which preserve the characteristic structure, distinctiveness, and proportions of each individual letter_.
The letter-craftsman must have a clear idea of the _skeletons_ of his letters. While in every case the precise form which commends itself to him is matter for his individual choice, it is suggested in the following discussion of a typical form--the Roman B--that the rationale of his selection (whether conscious or unconscious) is in brief _to determine what is_ ABSOLUTELY _essential to a form, and then how far this may be amplified in the direction of the_ PRACTICALLY _essential_.
The letter B reduced to its simplest (_curved-bow_) form--_i.e._ to the bare necessity of its distinctive structure--comprises _a perpendicular stem spanned by two equal, circular bows_ (_a_, fig. 160).
In amplifying such a form for practical or æsthetic reasons, it is well as a rule not to exceed one's object--in this case to determine a reasonable (though arbitrary) standard essential form of B, having a distinctive and proportionate (_f_) structure. We may increase the arcs of the bows till their width is nearly equal to their height (_b_), make their outer ends meet the ends of the stem (_c_), and their inner ends coincide (_d_). Raising the division till its apparent position is at or about the middle of the stem entails a _proportionate increase_ of width in the lower part, and a corresponding decrease in the upper part (_e_).