The San Francisco call., 1901-12-15

marine boilers Of the latest improved
Scotch, locomotive type or water-tube, for
burning either coal or crude petroleum;
ratus, evaporators, refrigersrting and Ice
machines, steering engines WindlaSSeS,
winches, coal and ash handling machinery
and, in fact, all that goes to operate an
ocean-going steamer Of the largest and
most elaborate type.
Mining Machinery.
The third or mining machinery class Is
so broad that only a bare mention can be
made of the various types. For mining
proper there are hoisting and pumping en-
rock-drilling, tramway and ventilating
machinery. For ore reduction there are
smelling furnaces for silver, lead and
roasting furnaces, revolving and kiln ore
dryers, stamp mills, roller mills. concen-
traitors and chlOrtnatiOn works Among
the Spec1alt1eS in this line manufactured
by the Risdon are Bryan roller mills,
Johnson concentratOrs, steel whims, Hos
kins giants, Wright calcini1g furnaces.
Evans hydraulic elevators Among the
different methods of mining one In partic-
ular has become of paramount Importance
in the last few years. 1t is working the
bucket and even caisson dre1gers.
The Risdon has built great number
OF those and holds the exclusive rights
for building the r. H POstlethWafte
dredge, undoubtedly the most successful
one on the market AS evidence Of This
might be stated the fact that four years
working in California, although many
were LETT as failures on the banks OF riv-
ers throughout the State
Since the first RisdOn drediyer was built
on the Feather River there have been
over thirty Of them made, and the Ris-
don Is now building nine CT these ma
cnlnes. The dredgers have not only been
used IN California but are in operation
all over the Western States and among
the gold districts Of Africa. Alaska and
Structural Iron Work.
In the fourth class-that Of structural
iron and steel work-the Risdon has con-
tributed to the most important recent
building operations Of San Francisco, no
and the Claus Spreckels building.
=. Mention should also be made Of the
Spreckels Sugar Company plant at
The main building is $50 BY '1OS feet. six
stories nigh and contains over $500 tons Cf
structural steel.
Engine and Machine Work.
The last class, comprising miscellaneous
engine and machine work, contains many
diverse branches, some, notably sugar
machinery and hydraulic machinery be-
ing almost of sufficient IMPORTANCE ana
magnitude to rank with the main groups.
Inc former includes most Of the machink
cry used on the sugar plantations Of IL
Hawaiian Islands, consistins of crushers
vacuum pans, filter pres ses. settIing
tanks. etc, besides engines trash burn
ing boilers, pumps, water wheels, motors.
etc.
IN hydraulic machinery the Risdon Is
pioneer, having built the real prototype
of the modern tangential water wheel with
reaction buckets, frequently e@IlsA the
''Pelton type" water wheel They have
built these extensively for MANY wears
the later example being three 5000 horse
power water wheels, directly connected to
polyphase alternators for the Bav Coun-
ties Power Company. Another innDortant
branch is that of hydraulilc steel pine
building. of which they are the most ex-
tensive builders in the world
The miscellaneous group is too exten-
SlVe ana diversified to allow of specifying
more than a rev types For instance,
1oTllSs engines, FlSdon air cOmpreSsOrS.
Aeine sa1ety watertube boilers, Smith
Valle pumps. all sorts Of manufacturing
ana speclal machinery, boiler fixtures, all
klnds ana sizes or valves, pneumatic and
hydraulic tools.