Horizontal beams

[Bruno Tournay]

Hello everybody.
This is my very first message on this mailing list, so I would like first to 
say shortly how I appreciate Lilypond software... Its two main qualities for me 
are the very very nice output result and its tuning possibilities.
Also I found the support for drums/percussion score is unique.

Now my question is: how can I get horizontal beams ?
Recently I upgraded from version 1.4 to 1.6 (1.6.4). With version 1.4 I was 
using the following beam properties:
  \property Voice.Beam \set #'height = #0
  \property Voice.Beam \set #'staff-position = #4

In v1.6 the height property has disappeared. In documentation, I saw something 
called damping, but I'm not even sure of its purpose... I tried to set it to 
100000 (as said in doc: "100000: horizontal beams"). I think it actually 
changed the shape of the beam, but it is still not horizontal.

What can I do ? Am I doing something the wrong way ???

Thank you in advance for your help.
  Bruno.