Script Analysis - Ascender and Descender Height

In Script Analysis - Fundamental Error and Script Analysis - The new measurements I talk about my new (correct!) measurement of the nib width, and find the x-height to be 5 pen widths.

The next thing to do is to look at the ascender/descender heights.

Here are scanned copies of my 4 images I have to work on. They have all been re-sized so that the x-height of each line is 5 pen widths - 7 mm, using a 1.5 (or 1.4 !) mm nib width.

Historical Source Book/The Illuminated Page, (Backhouse, page 164) ::-Codices Illustres page 287::-

British Library online Image 1 ::-

British Library Image 2 ::-

I've marked up my measurements of all the ascender and descender heights.

It would have been nice if they had all been the same, but oh well. The ascender/descender (a/d) heights varied from 2 mm to 3 mm, with 1 measurement on one page at 1.5 mm, and one on another page at 4 mm.
I've looked in the past for some correlation between these different heights and the placement of other objects on the page (eg the illuminated letter) and been unable to find one.

I've written at the bottom of each scanned page the number of occurences of each of the measurements (5 x 2.5 mm, 10 x 3 mm, 3 x 3.5 mm sort of thing, remembering there are 18 lines on each page).

The most common value (the median value) is most definitely 3 mm, so that's what I'm taking for my a/d height. Translating to pen nib widths, this is 2 pen nib widths.
The total measurement including the ascender, x-height and descender is 9 pen widths, or 13 mm for a pen nib width of 1.5 mm.

The above answers the following questions from my list of script analysis questions :

"Pen Nib Width

Using a page of the mss reproduced at the real size of the mss for all of this section :-

What is the size of the pen width in millimetres/inches? (measure from a broad stroke of the O). This is handy to know when ruling up a page... ²

How many pen widths are there between the baseline and waistline?^3,4
(This should be the same as the number of pen widths of the height of the O)
This is the x-height.

Select a pen with the appropriate nib width, and check your measurement by drawing a nib ladder on the reproduction of the mss page

How many pen widths are there between each of the baselines of the text, disregarding ascenders and descenders? What is this distance in mm/inches?^1,3,4

What is the ascender height in pen widths and mm/inches?^1,3,4

What is the descender height in pen widths and mm/inches?^1,3,4

It may be that the x-height, ascender and descender heights frequently vary by a couple of millimetres on the page being inspected because the page was ruled by hand, and also because the original scribes made mistakes as well. Take the most common measurements."

OK,. so I forgot to do the nib width ladder. oops.