Material Type

Artifact

Other Name

STEVENSON SCREEN

Date Range From

1960

Date Range To

1970

Materials

WOOD, ALUMINUM

No. Pieces

1

Height

74.5

Length

73.6

Width

52.1

Description

RECTANGULAR WOODEN BOX, PAINTED WHITE. ALL SIDES FORMED WITH SLANTED SLATS OF WOOD, AS PER VENT/GRATE. TOP IS ANGLED, AND RAISED TO ALLOW FLOW OF AIR. ONE SIDE PANEL IS HINGED AT BOTTOM; CLOSES BY MEANS OF RING AT TOP FOR PADLOCK. INTERIOR HAS LENGTH OF ALUMINUM PIPE, "L"-SHAPED, EXTENDING VERTICALLY THROUGH TOP OF BOX. PIPE HAS BRACKET AND OTHER FITTINGS FOR CONNECTING INSTRUMENTS (NOT INCLUDED). INTERIOR ALSO FITTED WITH THREE VERTICAL PIECES OF WOOD; TWO HOOKS ON EACH. VARIOUS SCREW HOLES IN LEGS OF BOX. PAINT SCRATCHED AND MARRED THROUGHOUT.

Subjects

METEOROLOGICAL T&E

Historical Association

INDUSTRY

History

OPERATED BY ENVIRONMENT CANADA AT LETHBRIDGE'S KENYON FIELD FROM 1960 TO 1996. THE SCREEN HELD VARIOUS INSTRUMENTS TO GATHER METEOROLOGICAL INFORMATION. ENVIRONMENT CANADA'S LETHBRIDGE WEATHER OFFICE WAS CLOSED MARCH 31, 1996 WHEN ITS WEATHER GATHERING SERVICES WERE TRANSFERRED TO CALGARY. *UPDATE* IN 2010, NICOLE HEMBROFF, COLLECTIONS ASSISTANT, CONDUCTED A SURVEY OF PALLET RACKING. SHE MET WITH RICK SHEWCHUCK, WHO USED TO BE AN EMPLOYEE AT THE KENYON FIELD WEATHER STATION, TO DISCUSS THE STEVENSON SCREEN. SEE BELOW. ACCORDING TO RICK SHEWCHUK THE STEVENSON SCREEN HELD 4 THERMOMETERS: A DRY BULB, A WET BULB, A MAXIMUM AND A MINIMUM. MOST STEVENSON SCREENS WERE ALSO LOCATED NEAR TO RAIN AND SNOW GAUGES AND AN EVAPORATION PAN. THE DRY BULB AND WET BULBS WERE READ EVERY HOUR. THE DRY BULB MEASURED AIR TEMPERATURE AND THE WET BULB PROVIDED THE DATA FROM WHICH HE COULD CALCULATE HUMIDITY AND DEW POINT. THE WET BULB HAD A WICK OVER THE MERCURY PORTION OF THE THERMOMETER. THE WICK WAS ALWAYS DAMP. DURING THE WINTER, WHEN THE DAMP WICK WOULD FREEZE, SHEWCHUK HAD TO MANUALLY WET IT AND WAIT UNTIL IT COOLED DOWN BEFORE TAKING HIS MEASUREMENTS. A MOTOR DROVE AIR BY THE WET AND DRY BULB TO KEEP THEM VENTILATED. VENTILATION ENABLED MORE ACCURATE READINGS OF THE INSTRUMENTS. THE MAXIMUM THERMOMETER HAD A KINK IN THE COLUMN. AS THE TEMPERATURE WARMED, MERCURY WOULD BE PUSHED OUT OF THE BULB. HOWEVER, AS THE TEMPERATURE DROPPED, THE KINK IN THE COLUMN WOULD PREVENT THE MERCURY FROM COMING DOWN. THUS, IT PROVIDED A MAXIMUM TEMPERATURE. IN ORDER TO RESET THE THERMOMETER, SHEWCHUCK WOULD HAVE TO SHAKE IT TO FORCE THE MERCURY BACK DOWN INTO THE BULB. THE MINIMUM THERMOMETER DID NOT HAVE A MERCURY BASED SOLUTION INSIDE ITS COLUMN. INSTEAD, IT UTILIZED AN ALCOHOL BASED SOLUTION. THE MINIMUM THERMOMETER HAD TO REST ON ITS SIDE TO WORK. IT HAD A MARKER IN IT THAT DROPPED AS THE TEMPERATURE DROPPED. HOWEVER, WHEN THE TEMPERATURE INCREASED THE MARKER DID NOT MOVE. THUS, A MINIMUM TEMPERATURE COULD BE DETERMINED. IT WAS RESET BY TURNING THE THERMOMETER UPSIDE DOWN. WHILE THE WET AND DRY BUBS WERE READ EVERY HOUR, THE MAXIMUM AND MINIMUM BULBS WERE ONLY READ ONCE EVERY SIX HOURS. THIS SIX HOUR READING WAS CALLED A SYNOPTIC OBSERVATION. AFTER EACH SYNOPTIC OBSERVATION THE MAXIMUM AND MINIMUM BULBS HAD TO BE RESET. THE PURPOSE OF THE STEVENSON SCREEN WAS BASICALLY TO HOLD THE TOOLS LISTED ABOVE. IT WAS PAINTED WHITE TO REFLECT SUNLIGHT. IN THE SIMPLEST OF TERMS, THE STEVENSON SCREEN PROTECTED THE TOOLS IT HOUSED FROM THE ELEMENTS. THE SCREEN WAS JUST ONE OF THE BASIC THINGS ABOUT OBSERVATION. IT WAS EASY TO USE. THERE WAS A REMOTE SWITCH TO TURN ON THE FAN. ACCORDING TO SHEWCHUCK, “WHEN YOU GOT THERE [TO THE STEVENSON SCREEN] IT WAS PROPERLY ACCLIMATIZED. YOU JUST OPENED THE DOOR AND TOOK THE READING.” IT DID REQUIRE MAINTENANCE FROM TIME TO TIME. FOR EXAMPLE, IT HAD TO BE REPAINTED, MUSLIN HAD TO BE CHANGED AROUND THE WET BULB, AND MORE. A PARTICULAR PROBLEM WITH REGARD TO ALBERTA WAS THE AMOUNT OF FINE DUST THAT WAS KICKED UP BY THE WIND. THERE WAS A SCREEN AT THE END OF THE VENTILATING TUBE THAT WAS OFTEN COMPLETELY BLOCKED BY DUST. THE DUST HAD TO BE CLEARED OCCASIONALLY TO ENSURE PROPER VENTILATION. ACCORDING TO SHEWCHUCK, LETHBRIDGE’S INTENSE WIND DID NOT JUST CLOG THE VENTILATION TUBE. HE USED TO GET CALLED FROM PSYCHIATRISTS WHO WERE CONCERNED ABOUT THE WIND’S INFLUENCE ON SUICIDE AND DEPRESSION RATES. HE ALSO GOT CALLED BY TRAVELERS, FARMERS, THE MEDIA AND MORE, ALL OF WHOM WANTED TO KNOW HOW THE WEATHER WOULD AFFECT THEIR CITIES, ROADS AND LIVES. USUALLY ANY REPORTS HE DID TOOK PLACE THROUGH CJOC, CFCN ETC. DORI ROSSITER, MARK CAMPBELL, LEO DALL AND DAN GERMAINE ALL INTERACTED WITH HIM ABOUT WEATHER MATTERS. HE EVEN FILLED IN FOR THEM AT THE STATIONS SOMETIMES. THE LETHBRIDGE WEATHER OFFICE ALSO HAD A GOOD CONNECTION WITH THE MEDICINE HAT STATIONS. THIS PARTICULAR SCREEN WAS LOCATED BETWEEN THE HIGHWAY AND THE AIRPORT TERMINAL AT THE CURRENT AIRPORT LOCATION. IT WAS KEPT IN A FENCED IN AREA. IT WAS LIKELY IN USE FOR THE DURATION OF THE EXISTENCE OF THE LETHBRIDGE WEATHER OFFICE. IT WOULD HAVE BEEN STANDARD ISSUE FROM THE FEDERAL GOVERNMENT. THEY WOULD HAVE SENT SOMEONE OUT TO MAKE SURE IT WAS PROPERLY INSTALLED IN A CONCRETE BASE. THE WEATHER OFFICE WAS SHUT DOWN IN 1996 BY ENVIRONMENT CANADA. NEW TECHNOLOGY HAD COME ALONG. ACCORDING TO SHEWCHUCK, “EVERYTHING IS DIGITIZED NOW… EVEN THE VOICES.” 37 WEATHER STATIONS ACROSS CANADA WERE SHUT DOWN BECAUSE THE NEW TECHNOLOGY DIDN’T REQUIRE AS MANY BRIEFERS AS BEFORE. EVEN THOUGH MANY OF THE INSTRUMENTS HAVE GONE DIGITAL, STEVENSON SCREENS ARE STILL IN USE TODAY. SHEWCHUCK WORKED WITH ENVIRONMENT CANADA FOR THIRTY-FIVE YEARS. FROM1960 UNTIL HE RETIRED FOR THE FIRST TIME IN 1995. TWENTY-THREE OF THOSE THIRTY-FIVE YEARS WERE SPENT IN THE LETHBRIDGE WEATHER OFFICE. WHILE HE IS CURRENTLY A TRUCK DRIVER, HE STILL STUDIES WEATHER MAPS. SHEWCHUCK GREW UP IN BELLIS, AB. WHEN HE GOT OUT OF HIGH SCHOOL HE DIDN’T KNOW WHAT HE WANTED TO DO. SOME OF HIS SCHOOL MATES WENT TO TAKE WEATHER OBSERVATION. THEY TOLD HIM ABOUT IT. HE WAS INTERESTED SO HE WENT TO DO AN INTERVIEW IN EDMONTON, AB TO GET INTO THE WEATHER OBSERVATION PROGRAM. HE TOOK HIS FIRST COURSE AT THE MUNICIPAL AIRPORT IN EDMONTON. ACCORDING TO SHEWCHUCK, “THERE WAS ALWAYS SOMETHING NEW TO LEARN.” WEATHER OBSERVATION SUITED HIS INQUISITIVE NATURE. IN 1960 SHEWCHUK TRAINED IN EDMONTON, AB FOR THREE MONTHS. HE LEARNED ABOUT SURFACE METEOROLOGY DURING THAT TIME PERIOD. FOLLOWING THAT HE FLEW IN THE TRANSPORT CANADA NORTH STAR TO TORONTO. HE TOOK THREE MONTHS OF TRAINING IN UPPER AIR METEOROLOGY. IN FEBRUARY 1961, SHEWCHUCK WAS POSTED TO FT. SMITH, NWT FOR THREE MONTHS. HE WAS THEN SHIPPED TO BANKS ISLE, NWT WHERE HE SPENT FOURTEEN MONTHS. THEN HE SPENT EIGHT MONTHS IN FORT NELSON, BC, WHITEHORSE, YK AND FT. SMITH NWT. DURING HIS TIME THERE HE DID RELIEF RADIOSONDE OBSERVATION. HE SPENT ANOTHER FOURTEEN MONTHS IN ALERT, NWT (ELLESMERE ISLE) AT THE ARMY BASE. THEN HE APPLIED FOR A POSITION WITH ICE RECONNAISSANCE. HE WENT TO TORONTO FOR THE COURSE IN JUNE OF 1965. HE SPENT 4 YEARS ON ICE PATROL. HE COMPLETED 2000 HOURS OF ICE RECONNAISSANCE IN AIRCRAFT. THIS JOB TOOK HIM ALL OVER CANADA. HE COMPLETED TWO ICE BREAKER TOURS. ONE WAS ON THE CCGS D’IBERVILLE WHICH TRAVELLED FROM QUEBEC CITY, QUEBEC AROUND LABRADOR, COVERING THE HUDSON BAY AND MAKING IT FAIRLY CLOSE TO EUREKA (ELLESMERE ISLE). HE DID SOUNDINGS ON BAFFIN ISLE. HE ALSO DID AN ICE BREAKING TOUR ON THE CCGS CANSELL IN VICTORIA, BC. THAT SHIP WENT AROUND ALASKA. HE SCOUTED ICE WITH THE AID OF A HELICOPTER TO LET PEOPLE KNOW WHAT THE EASIEST WAY TO TRAVEL THROUGH THE OCEAN WAS. AFTER GETTING MARRIED IN FALL OF 1968 HE TOOK A COURSE IN OTTAWA ON BRIEFER PRESENTATION. THEN HE WAS STATIONED IN YELLOWKNIFE NWT UNTIL FEBRUARY OF 1973. WHILE THERE HE BRIEFED PILOTS, MEDIA, THE CBC AND MORE ON WEATHER INFORMATION. HE ALSO HAD HIS CHILDREN THERE. SHEWCHUCK WANTED TO LEAVE THE ARCTIC BECAUSE HE THOUGHT IT WOULD BE BETTER FOR HIS FAMILY. HE APPLIED FOR A TRANSFER AND ENDED UP IN LETHBRIDGE IN FEBRUARY OF 1973. WHILE AT THE LETHBRIDGE WEATHER STATION HE WAS RESPONSIBLE FOR MONITORING WEATHER AND DISTRIBUTING IT TO THE MEDIA, FARMERS, AND MORE. HE OFTEN DID FIFTEEN MINUTE WEATHER SPOTS ON CABLE TV. CLARE MARTIN WHO NOW WORKS FOR CBC WEATHER GOT HER FIRST TASTE OF TV WORK IN LETHBRIDGE AT THE WEATHER STATION DURING ONE OF THESE 15 MINUTE SPOTS. DURING HIS TIME AT THE WEATHER STATION IN LETHBRIDGE, SHEWCHUCK TOOK MANY COURSES ABOUT WEATHER IN OTTAWA, ONT. THE MAIN WEATHER TRAINING SCHOOL IS IN CORNWALL, ONTARIO.

Catalogue Number

P19960104000

Acquisition Date

1995-09

Collection

Museum

Less detail