hose outlets and with 8-inch gated connections to the mains; to be so distributed that the entire area of the district is protected and the average area served per hydrant shall not exceed 40,000 square feet.

For each 10 per cent of combined adequacy and reliability of the High Pressure Fire System, deduct a percentage of the total points under Structural Conditions (after deducting Item 21) on the following basis:

For fire flow available at 250 pounds, 7.5 per cent; for fire flow available at 200 pounds, 6.5 per cent; for each 10 pounds under 200 pounds pressure, down to 90 pounds, at which fire flow is available, use a percentage 0.5 less.

Where the piping system is dry during a part of the year, only the above percentage of credit will be allowed.

Note. The value of a High Pressure Fire System to be determined on the basis of fire flow; when the system furnishes supply for other than fire purposes, fire flow shall be considered as the amount available after allowing for such other uses. The system shall be graded on the basis of a possible total deficiency of 1,000 points, application being made as under Water Supply, except as modified below:

Item 5. Use Deficiency Scale for means of notification of repair gang, competent officials and any pumping station.

Item 6. a and b to be based on maximum quantity available in the district at the weakest point in the system, whether due to poor gridironing or elevation.

a. For fire flow at time of average domestic consumption:

Use 2 times Deficiency Scale.

Item 16. To be for maximum effect on fire flow at the same pressure used under Item 6 a and b.

Items 20, 21, 22, 23, 26 c and d, 29 and 31 b. Not to be applied.

Under each item the application must include any additional points due to deficiency of the plant furnishing power.

Per cent of combined adequacy and reliability

1,000-points of deficiency.
1,000

ADDITIONAL DEFICIENCIES

Adverse climatic conditions. Items 1, 2, 3 and 4 to be based on average conditions for at least a 10-year period, if available. Where no weather bureau station is located in the city, use the average for the closest two or three stations.

Apply only for the months having an average of 10 days or more with a maximum temperature of 32 degrees

For each day having a maximum temperature of 32 degrees or less.

1

4. Hot dry weather:

Apply for the months having an average mean maximum temperature of 65 degrees or more, with 6 or less days of .01 inch or over of precipitation. Deficiency to be based on

m = Average number of months per year.

t Average monthly mean maximum temperature.

d = Average number of days per month with 0.01 inch precipitation.

5. Unusual or exceptional conditions. Apply for conditions not measurable by the climatic conditions above, which offset protection and increase the probability of starting fires: These to include frequency and extent of forest fires which might extend into the city; tornadoes, hurricanes and cyclones which result in numerous fires or interruption of fire service; blizzards and severe snow storms which impede operation of the fire department; earthquakes of such intensities as to injure buildings, water mains and cause numerous fires; mine cave-ins affecting extensive areas, and floods which cover part of the district considered or cause wide detours of fire apparatus.

On the basis of numbers; one each 10 years shall be classed as seriously frequent, and one each 20 years moderately frequent; the extent or effect of the conditions shall increase or decrease this proportionately.

Use 14 times Deficiency Scale.

Difference in grading of water supply and fire department.-Where the fractional classes corresponding to the points of deficiency of the water supply and fire department, that is, the points of deficiency divided respectively by 170 and 150, differ by 3 classes or more, there shall be added to the total points of deficiency a certain number of points varying with the amount of divergence between the classes of the two features. The number of points to be added shall be determined by the following table, proportioning for fractional divergence in classes: