My father was, among other things during his working life, a "finish carpenter," meaning he did finishing work--interiors, mouldings, trim, all requiring precise measurement and a knowledge of how to work with walls that were not plumb or level and still make the end product look right. I was always impressed by his ability to look at a gap or hole or bolt and tell what size it was down to a 1/16 of an inch. He'd eye the head on a bolt and say, "Three-eighths." I helped him for years and never knew him to be wrong. He could level a piece, put the level on it and say, "Throw the level away--we don't need it." He was that good.
In recent years, when he has been unable to do the carpentry work he excelled at, I asked him how he developed such a keen eye for measurement. Typically modest, he shrugged and said, "I don't know. Just by doing it, I guess."
I recently have come to understand how it was done as I am nearing the end of my fence project (ran out of pickets today and have to wait a week for more to come) in which I have been converting our old security fence to a picket fence. (I will post an illustrated guide to doing this next week in case you'd like to know how it's done). I am not terribly skilled at this sort of thing. I have been working on it in fits and starts since last October, but I have about three more hours' work and it'll be done except for the gates, which I deferred until I better knew what I was doing. I have redone some sections four times to get them right. There are so many complexities to erecting a fence, much less a scalloped picket fence. And recently I am finding myself with some of my father's sense of measurement.
I mark off the distance between the pickets on the top stringer (horizontal piece that goes between the fence posts to which the pickets are attached). On the last section, which I marked today, I found the pickets did not come out evenly when I used a 1 3/4 inch spacing. To make them fit, I had to gain 2 and 1/2 inches over an eight-foot section of fence. Using higher math, I calculated that the pickets needed to be 1 7/8 inches apart. I started out using my rule to add an eighth of an inch to each width. After about three changes, I thought, I can look at it and mark an eighth of an inch. And I did. Then it occurred to me I was doing, in a small way, what my dad was able to do. Working with the fence had given me the practice to know how to "eyeball" a small measurement.
And so it is with writing. The experience we as writers gain when we read other writers or as we write enables us to have a sense of what is right for what we're writing. We might prune a descriptive section that is bogging down a story, or we might add some exposition to move the story along. We might not be able to think of the word we want and put a pale substitute so we can keep writing and come back later with the right word. And, just as my fence should, with any luck, be a work of beauty, so can our writings be beautiful, true and excellent. That is my wish for myself, and for all my colleague writers. And that's how it's done.