SCIENC 
NEw SERIES. 
Fripay, Drecemper 10, 1897. Testa Se 
VoL. VI. No. 154. 
Physik. Institut / U 
d. Univers, Wirzburg, 
4 
oe 
Cin Os CR Ey ee 
elec getter ten fin! 
Gres as Breit aa getcinste K- Bithlr 
Wile. Carr a 0 Pe peiin, bie Tox Ore Viselhe 
that atm stlés funk thn gut Ceishet tne) 2% frate 
Hor Ure Chin Rrnsuiende Creactep Lam Vicgubiamery 
Jetornleog rieaeshe . Me 72.tdev TuctrHern 
ea Attuuns 
OY lene 
Se, va FV Og, LBA ae en 
Le rnduek. Ve sais arab aiten to telabarn Sieie 
to, Clan Vrlnin what. Arte, 
GetaAhevuy mall, 
TRANSLATION. 
MEssrs. QUEEN & Co., Philadelphia. a) - 
GENTLEMEN: WE “lye A ler. 
I beg to thank you for the X-ray tube pre- ri 
sented to my laboratory. It has worked very 
satisfactorily, and I find the principle you have 
applied to the regulation of the vacuum especially 
ingenious. The images would be even sharper 
if the platinum plate of the cathode were abso- 
Jutely plane and polished. Please let me know 
at what price you can furnish me these tubes. 
Yours truly, 
PROF. DR. W. C. ROENTGEN. 
