General Information

Serial #

N/A

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

wood, metal, synthetic, string and mercury materials of construction.

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

17.8 cm

Width

10.8 cm

Height

36.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Forestry

Category

Fire fighting

Sub-Category

N/A

Manufacturer

AKA

Great Lakes

Country

Canada

State/Province

Ontario

City

Sault Ste. Marie

Context

Country

Canada

State/Province

Ontario

Period

Used in late 1970s.

Canada

This device was designed by Canadian Forest Service, Great Lakes Forestry Centre, and used in experimental fires in Ontario.

Function

To measure the rate of spread of fire in experimental burning plots.

Technical

This device allows the used to mechanically calculate the rate of spread of fire in experimental burning plots. the rate is calculated by simply dividing the spread distance in metres by the period of observation in minutes. Separate estimates of rate of spread are made for each fuel type or topographic unit in plots. Rate of spread is often estimated by timing the movement of the fire front between two points (ie. rocks or snags], of known distance. Where faster moving fires are anticipated (>10m/min), a grid system is set up on the site before the burn, and a stopwatch is used to determine how long it takes the fire to cover a predetermined distance. This device eliminates the need to use a stopwatch. Instead, the devices are buried in ground on a grid in a plot. When fire arrives at a location, it burns the string extending from the box, which drops the mercury switch inside to activate the encased clock. After the fire, the devices are retrieved and the time of arrival of fire recorded from the clock. An average spread rate of fire is determined based on plot times. (ref. 1)

Area Notes

Unknown

Details

Markings

"19" handwritten in black marker on box (casing) top.

Missing

None.

Finish

Unfinished wooden box has plexiglass window in one end; metal hinge permits access to switch compartment. Box top fitted with string and metal hardware. Metal and synthetic clock; metal, synthetic, string and mercury components used in construction of switch.

Decoration

N/A