Michael did not say there was no histogram.  He found it awkward to get at.  Here is a quote from Michael.

"Fortunately there is a work-around. Set the camera for at least 10 second review and then when the image appears press the green Display button. This will call up the review display a couple of seconds later. Now press the Info button. If you've programmed the Info button to display a histogram it will now show up. This takes two button presses and a few extra seconds, but it does solve the problem."

I think what Michael was getting at was The E1 does not have a quick review mode where the histogram is automatically displayed with the picture immediately after taking it.

Michael Reichmann's "OLYMPUS E-1 A Hands-On Field Report" criticizes the E-1 as not having a picture review histogram???

In fact, it HAS A HISTOGRAM!!!!  Just push the info button and use the sub dial to get to the histogram!!!

In fact, the histogram is a little easier to get at than Michael's description (he might have had an early version of firmware); regardless of the review setting,
- wait until the card activity light stops flashing
- press review button
- press INFO button.
(assuming you have set INFO to histogram mode.)