AmDec"  1879™ }        Perimetric  Dimension  System,  595 
Accurate  to  a  fraction  of  a  millimeter,  the  gauge  becomes  an  in- 
strument of  precision,  adapted  to  ascertaining  the  perimeters  of  a 
great  variety  of  forms,  and  to  expressing  their  values  in  uniform  terms. 
It  has  the  special  advantage  of  utilizing  old  appliances,  for  by  it 
their  equivalence  under  the  general  system  may  be  at  once  determined. 
Contrasted  with  the  ordinary  gauge-plate,  the  Adaptable  Gauge  will 
be  seen  to  be  possessed  of  important  advantages.  The  former  is  capa- 
ble of  measuring  cylindrical  forms  only,  and,  as  made,  is  often  inaccu- 
rate and  always  very  limited  in  its  range  of  sizes.  The  Adaptable 
Metric  Gauge,  on  the  contrary,  beside  being  accurate,  is  practically 
unlimited  in  capacity,  measures  cylinders  perfectly,  and  is  equally  well 
adapted  to  the  measurement  of  instruments  of  irregular  outlines — as 
urethrotomes,  metrotomes,  separable  dilators,  divulsers,  folding  specula 
and  the  like.  While  the  gauge-plate  is  difficult  of  verification,  the 
correctness  of  the  Adaptable  Gauge  may  be  instantly  tested  by  com- 
parison with  any  standard  metric  rule. 
109  South  Eighth  Street,  1 
Philadelphia,  June  ioth,  1879.  J 
Charles  H.  Thomas,  M.D. 
Dear  Doctor — We  are  now  using  your  Adaptable  Metric  Gauge  as  a 
•correct  guide  in  the  manufacture  of  urethral  and  dilating  instruments. 
It  has  been  particularly  serviceable  in  enabling  us  to  bring  the  measure- 
ment of  bougies,  catheters  and  all  urethral-cutting  instruments  to  the 
point  of  absolute  accuracy. 
Thanking  you  for  bringing  the  gauge  to  our  notice,  we  would  state 
that  we  have  made  arrangements  to  produce  them,  and  should  be  most 
happy  to  furnish  members  of  the  profession  with  your  very  useful 
appliance  gratuitously. 
Your  views  in  regard  to  a  Universal  Scale  are  so  evidently  correct 
that  we  are  prepared  to  conform  to  them. 
We  are,  very  respectfully,  yours, 
J.  H.  Gemrig  &  Sons. 
They  will  also  be  furnished,  without  cost,  upon  application  to  Messrs. 
George  Tiemann  &  Co.,  New  York  City ;  D.  W.  Kolbe  &  Son, 
Philadelphia,  Pa.;  Sharp  &  Smith,  Chicago,  Ills.;  or  the  American  Metric 
Bureau,  Boston,  Mass. 
(From  "  Philadelphia  Medical  Times."    Revised,  with  additions,  by  the  author.) 
