Not all names could be deciphered.

The oldest signatures are from 1927, after the Colloquium had moved from Ehrenfest's home to the theory institute on the Langebrug. Older signatures are still preserved in the guest bedroom of the Ehrenfest house on Witte Rozenstraat.

Here is a photograph of the old wall behind a blackboard, from 1950, before the wall was moved to the new Instituut-Lorentz on Nieuwsteeg. The deep horizontal scratch was made by a student of Ehrenfest after failing an exam, as recalled by Casimir in his biography.

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Joseph O. Hirschfelder Nov. 11, 1953
M.J. Klein 1958
Guy Paquette 58-59
Walter B. Ford 1 X 28
Felix Bloch X 29
David Pines 58
L.C. Jackson April '30
E. Fermi 11/1/1932
W. Heisenberg 12.12.35
E. Montroll 1956
Paul Erdos 25 oct 1948
W.V. Houston Aug 25, 1954
K.S. Krishnan 25 8/54
E. Back 12.6.29
L. Nordheim 4 X 29
Max Planck
W. Opechowski (1958)
Ch. Fabry
P.G. de Gennes 1961
Jan Korringa 6 VI '61
Leon W. Cohen 24 VI 30
R. Peierls 20 III 30, 24 IV 61
M. Polanyi 22.5.1933
Arnaud Denjoy 25 Octobre 1948
Volker Heine '61
D.K.C. MacDonald 1960
L.C. Schiff 5 V 54
Lars Onsager 1 VII 49
W. Pauli 25 IX 28
V.L. Telegdi 4/IV/60
J.M. Luttinger 1958
I.I. Rabi 18/IV/1928
P. Debije 16/9 '29
W.L. Bragg 1/4/30
Rayleigh 9/4/30
Pierre Auger 14/3/33
Francois Perrin 5/4/33
Harold C. Urey 16/12/47
I. Prigogine 47
H.A. Tolhoek Nov. 1953
M. Born 5 V 28
David M. Dennison VI 1927
Ernest O. Lawrence 22 VI 37
P.A.M. Dirac VII 27
Pascual Jordan 7 VII 27
Irving Langmuir 2 Nov. 27
W. Bothe 9.5.28
John Hasbrouck Van Vleck 3-3-30
Nevill Mott 11.2.46
L. Neel 13/12/49
Victor Weisskopf 10/4/51
I. Oppenheim 
Marc Kac 2-10-1959
Aage Bohr 21.9.1951
W. Heitler 2 Okt. 28
L. Landau 16 V 30
Meghnad Saha 25 VI 27
Bergen Davis VII 27
Robert Oppenheimer VII 27
W.L. Severinghaus July, 1927
R.C. Tolman August 22, 1927
Max Born Oktober 1927
A. Einstein Febr. 28
Jean Becquerel mai 1928
H. Hopf 8.X.48
John Ross 1966
E.M. Purcell May 1957
Roy Glauber July 1956
J. v. Neumann 22 IV 29
F. London 30 V 33
R. de L. Kronig 7.3.28
O. Klein 7.3.28
E. Schrodinger 21.3.28
Ivar Walter 9.6.28
E. Wigner 2.8.28
J. Franck 10.4.29
L. Rosenfeld 13.9.29