218 
ON  A  SAFETY  LAMP  FOR  LABORATORY  USE. 
and  so  placed  and  adjusted  in  relation  to  other  parts  of  the 
lamp,  that  no  part  can  become  excessively  heated,  and  yet  so 
as  to  afford  sufficient  heat  for  any  work  of  the  kind  that  may  be 
presented, — the  openings  below  and  above  for  the  supply  of  air 
and  escape  of  the  products  of  combustion,  being  securely  covered 
with  fine  wire  gauze,  of  about  2500  meshes  to  the  square  inch. 
With  certain  slight  alterations,  the  lamp  figured  under  «  Gas- 
kochlampen  "  in  J.  F.  Lume  &  Co.'s,  Berlin,  catalogue  of  chemi- 
cal apparatus — a  medium  size  of  which  is  represented  in  the 
annexed  figure — makes  a  cheap  and  convenient  lamp  of  this 
kind.  As  they  may  not  be  on  sale  in  this  country,  a  partial 
description,  for  the  convenience  of  those  who  may  desire  to  have 
them  made,  may  not  be  amiss. 
The  sides  are  of  a  single  piece  of  sheet  iron,  riveted  together 
where  the  ends  meet;  the  upper  and  lower  edges  are  bent  re- 
spectively upward  and  downward 
so  as  to  stand  in  a  good  position  to 
receive  the  moveable  brass  rings, 
a  a,  which  serve  to  hold  firmly  the 
wire  gauze  with  which  the  top  and 
the  bottom  of  the  lamp  are  covered. 
As  the  wire  gauze  will  occasion- 
ally require  to  be  renewed,  this  sim- 
ple mode  of  construction  seems  a 
very  convenient  one,  as  the  move- 
able rings  may  readily  be  taken  off 
and  replaced  whenever  new  gauze 
is  needed. 
The  tubulure,  b, — which  may  be  closed  with  a  cork — serves 
for  the  introduction  of  a  match  for  lighting.  The  nipple,  c,  com- 
municates in  the  interior  with  a  ring,  2J  inches  in  diameter, 
made  of  copper  tube,  and  placed  in  the  centre  of  the  lamp, 
inches  below  the  upper  gauze,  and  provided  with  small  perfora- 
tions in  the  upper  side,  for  the  escape  of  the  gas.  The  height 
of  the  lamp,  between  the  upper  and  lower  sheets  of  gauze,  is  5£ 
inches;  its  width  across  the  top  4  inches,  and  across  the  bot- 
tom 6  inches. 
The  only  alterations  which  I  have  made,  consist  in  the  addi- 
tion of  the  tubulure,  5,  and  the  wire  gauze  across  the  bottom. 
