14 SCIENCE 
illuminating gas for chemical purity, and 
for its heating and illuminating value. 
This has involved an investigation of the 
methods of testing gas and of the instru- 
ments employed in such tests. That is, of 
apparatus used or that may be used in 
testing for hydrogen sulphide, total sul- 
phur, ammonia, ete.; of gas calorimeters 
and of gas photometers and flame photo- 
metric standards. In connection with this 
the bureau has made a thorough study of 
the legal requirements in all the cities and 
states of the country and of the methods 
of testing and inspection in use, and has 
tried to formulate the results of these 
studies in such a way as to be useful in 
framing municipal ordinances or state 
laws on this subject. In this investigation 
a great deal of field work has been done, 
and some of the ablest and most experi- 
enced gas engineers and city and state in- 
spectors and members of public service 
commissions have cooperated with the 
bureau. The results of this investigation, 
which has already been in progress for 
more than two years, will be published in 
two bulletins, one on the specifications of 
different kinds of illuminating gas and the 
public regulation of its distribution and 
sale, and the other on the methods of test- 
ing of gas and gas meters. In this work, 
three of the divisions of the bureau have 
cooperated. 
Another investigation of great engineer- 
ing importance is that of the effects of 
stray earth currents (due generally to 
street railways) upon the corrosion of gas 
and water pipes and of reinforced con- 
erete structures. Experiments show that 
under certain circumstances such effects 
are not only real but serious. The bureau 
is doing a good deal of field work, as well 
as laboratory work on this subject, in 
order to learn the conditions under which 
the damage is greatest, and how best to 
[N.S. Vou. XXXV. No. 888 
remedy the trouble. The first public re- 
port of this work was made recently at the 
annual meeting of the American Gas Insti- 
tute, and believing the bureau’s work to be 
of great practical value, the institute voted 
to appoint a committee to cooperate with 
the bureau, and expressed the hope that 
the American Street Railway Association 
would do the same. Closely associated with 
the electrolytic corrosion due to stray elec- 
tric currents is the electrolytic self cor- 
rosion, which is under some circumstances 
very serious and which is often wrongly 
attributed to railway currents. Electro- 
lytic boiler corrosion, and the corrosion of 
metal lath used in building, are other ex- 
amples of the same thing. These are also 
being investigated, and will be the sub- 
jects of published reports. 
Another subject of great practical im- 
portance that remains to be studied is the 
life hazard in electric practise, and the 
proper regulations by states and munici- 
palities for the protection of the public. 
Much attention is given by the Board of 
Fire Underwriters to the question of fire 
hazard, and in protecting buildings from 
the fire risk much has been done incident- 
ally to reduce the risk to life. But too 
little attention has been given to the pro- 
tection of the public from high poten- 
tial power and lighting circuits, and few 
cities or states have legislated on the sub- 
ject. A thorough study of this question, 
made with the fullest cooperation of the 
electrical power companies and the manu- 
facturers of insulating materials, would 
yield results of great practical value, and 
open the way to municipal and state regu- 
lation and inspection. 
4. THE TESTING OF INSTRUMENTS AND MA- 
TERIALS 
Instruments and materials are tested by 
the bureau for the various departments of 
