(2) State horse-power desired, maximum and minimum, and character of machinery to be driven.

(3) Number of units required.

(4) If for driving an electric generator, state of what manufacture, speed, kilo-watt

FIG. 36.-Pelton water wheel; iron mounted type.

capacity and style of shaft; also, if possible, send drawing so that sub-base may
be designed.

(5) For other direct-connection drive, give speed required and size of shaft.
(6) For belted or rope drive, give speed and size of driven shaft and desired sizes
(diameter and face) of both driven and driving pulley.

(7) State whether electric current is to be used for power transmission or lighting purposes, or both.

(8) If automatic regulation is desired, give the probable load variation and frequency of changes.

(9) What type of mounting is desired; timber frame, semi-masonry, or ironmounted? See Figs. 36 to 38.

(10) Material to be supplied. State specifically how much of the following material is to be supplied:

For Timber Frame Mounting.-Wheel proper complete with buckets, shaft; pillow-blocks (3), two set collars, gate valve, rigid nozzle and nozzle tips; pulley and shaft coupling: also (special) deflecting nozzle; stream cut-off. needle nozzle; governor connections; taper nozzle and flange to main pipe. Framing-bolts and timber may be specified, but are usually procured and built at the site from drawings furnished by the wheel manufacturer.

For Semi-masonry Mounting.-Same material as above with the exception of

the timber and bolts, and add; sole plate and nozzle support, and cast-iron upper housing.

For Iron-mounted Type.-Same material as for timber frame mounting with the exception of the timber and bolts and add; upper and lower housings, floor-stands, and extended sub-base.

Pipe Line. State what (if any) part of this is to be supplied.

(11) State whether material is to be supplied in sizes suitable for mule-back transportation.

FANS AND BLOWERS

Blowing machinery may be divided into four classes, (1) the fan type, (2) the "positive" impeller or displacement type, (3) the piston or "blowing-engine" type and (4) special types, such as devices utilizing the fall of a column of water to compress entrapped air. Only the first two types are covered in the following "reminders," the other two do not offer apparatus of standard construction.

(1) Service and Capacity

State for which of the following services the blower will be required, and supply the data indicated.

(a) General. If computed or otherwise known, give the volume of air to be handled, pressure at which it is to be delivered, suction pressure if any, and temperature. State whether blower is to be run for short periods, or continuously over several hours or days.

(b) Foundry Cupola.-Give the number of cupolas, diameter inside of lining, number and size of tuyères, and pounds of iron to be melted per hour. (c) Blacksmith Forges.-State the number of forges and the kind of work they are engaged on.

(d) Fuel-oil Burning.-Give number of burners and pressure.

(e) Gas Fires.-Give number of burners and size of air tubes.

(f) Ventilating Rooms.-Give dimensions of room or rooms; state whether the fan is to be placed in wall or ceiling; state temperature of air to be exhausted, or describe use to which rooms are put. For disk fans to be built into walls, give thickness of wall so that flanges may be spaced to suit. (g) Larger Ventilating Systems.-The system of ventilation should be planned by a competent ventilating engineer. In case such information has not been obtained and it is desired that designs and proposals be submitted by the contractors (an expensive method of obtaining the same), plans of the building should be given, showing all windows, doors, stairways, elevator shafts, etc., together with a complete statement of the conditions and requirements.

(h) Mine Ventilating. The requirements must be submitted by a mining engineer.

(i) Mechanical Draft for Steam Boilers.-State whether forced or induced draft apparatus is desired; give number, horse-power, make and style of boilers, steam pressure and number in use at one time; diameter and height of stack and data as to draft carried or desired; if flues are long or constricted, describe same or send drawings; kind of fuel used, cost and quantity in long/short tons used per hour or 24 hours; feed temperature; how damper is controlled; number, kind and size of grates; air space; send sketch of boiler layout showing space available for blower. (j) Exhaust Systems.-State what fans are to be used for, and amount of work they are expected to do. If for shavings or dust from machines, give the number and kind of machines, distance from the machine to the exhausts, and also distance the material is to be carried from the exhauster to receiving vault. State if for long shavings or stringy material. If for dry kilns, give capacity of kiln.

(k) Hot Blast Apparatus.-State what it is to be used for. If for heating or ventilating see (g) above. If for drying, give kind of material and quantity to be dried in given time.

(2) Method of Driving

State which of the following methods of driving is to be used, and supply the data indicated.

(a) Belt Drive.-If the driving engine, shaft, etc., is already in place or decided upon, give the R.P.M. of the shaft and also, if in place or arbitrarily fixed, give the diameter and face of the driving pulley.

(b) Silent Chain Drive.—Follow (a) giving, if decided, data as to chain to be used.

(c) Direct-connection to Engine (or steam turbine). If engine is not to be supplied with blower, submit drawing to blower contractor so that extended

bed, etc., may be constructed to suit, and state the R.P.M. If engine is to be supplied with blower follow "reminders" on p. 133.

(d) Direct Connection to Motor.-If motor is not to be supplied with blower, submit drawing to blower contractor so that extended bed, etc., may be

FIG. 40.-Hand and position of blowers; all views from pulley side.

(4) Hand and Position

(a) For Disk Fans

State hand as shown in Fig. 39.

(b) For Centrifugal Fans

The terms "Right Hand" and "Left Hand" as referring to the "position"
of the discharge outlet of fans, are applied differently by the various
makers, but the notation given in the figure seems the most logical.
A sketch such as is shown in Fig. 40 should, therefore, accompany the
inquiry or order. Note that the direction of rotation of the fan is fixed
by the position of the outlet; it can readily be determined by remembering
that the air leaving the opening comes off at a tangent to the rotating rim,
or is thrown off, as it were, by centrifugal force. All views are shown from
pulley side.

(c) For Positive Blowers, Radial Type

Discharge is usually vertical; if a special arrangement is desired, send sketch.

(d) For Positive Blowers, Impeller Type

These blowers are built in two types, the vertical and the horizontal, but manufacturers have standard patterns which cannot well be altered. It is not always possible, therefore, to stipulate the type, but a preference may be indicated when calling for bids.

(5) Material to be Supplied

For the type of blower desired, state what items are to be furnished and also what are not to be furnished.

(a) Disk Fans

Fan with shaft; frame complete; wall bolts; pulley; pinion; coupling (flexible
or flange); engine (see p. 133), steam turbine, or motor (see p. 147).
"Skeleton" fans consist of fan wheel, shaft, pulley and two journals, suit-
able for building into brick or other housing.

(b) Centrifugal Fans

Fan with shaft and boxes; housing; anchor-bolts; pulley pinion; coupling (flexible or flange); engine (see p. 133), steam turbine, or motor (see p. 147); extended base; blast gate.

(c) Positive Blowers

Blower complete; anchor-bolts; pulley; pinion; coupling (flexible or flange); engine (see p. 133), steam turbine or motor (see p. 147); extended base; companion flanges on suction and discharge; blast gate.

(6) Number of Units Required

GAS, GASOLINE, ALCOHOL, CRUDE OIL, ETC., ENGINES

(1) Fuel to be used

(a) Natural Gas.

(b) Artificial Gas (coal-gas, water-gas, etc.).

(c) Producer Gas; describe fuel used, method of manufacture, and B.T.U. per 1,000 ft.

(d) Gasoline.

(e) Alcohol.

(f) Kerosene.

(g) Crude Oil. State whether of Petroleum or Asphalt Base (or, field from which obtained); and density in degrees Beaumé (or weight per cubic foot). (h) Distillate.

(2) Service. State in a general way the service the engine will have to perform; i.e., whether operating a machine-shop, pumping, generating electricity for