A horse-drawn hearse on runners, jet aircraft, steam locomotives, a demonstration of the principles behind orbiting space satellites...

It's all part of Ottawa's recently-opened Museum of Science and Technology, of the National Museums of Canada, which shows every promise of soon becoming an institute of the same calibre as the South Kensington Science Museum in London or Chicago's Museum of Science and Industry.

Particularly rich in transportation artifacts, the Ottawa counterpart of these two long-established institutions has sections on ships, horse-drawn and powered road vehicles, aircraft, railways, and a variety of pure-science exhibits and demonstrations.

The name is "museum", but the atmosphere is diametrically opposed to the mental picture usually created by the word. The spaciousness, the lighting, and the mural mood photographs, plus the large measure of do-it-yourself participation, are more reminiscent of the exhibit techniques of Expo 67 than a museum. Admission is free.

Here are displays that can be operated by pressing a button or turning a knob and which are devoted to scientific principles or natural phenomena such as the orbiting of satellites, the viscosity of liquids, and effect of light on colors.

Dr. David M. Baird is director of the museum. A geologist by profession, Dr. Baird possesses a fresh inquisitiveness and a never-say-die attitude to his charge, a priceless attribute in any museum official.

The collection of horse-drawn vehicles is especially fine and complete, boasting every style of the coach and wagon-builders' art of yesteryear. In funereal black, an elaborate hearse body, with interchangeable frames carrying wheels or runners, dominates the assembly of other vehicles employed on happier occasions.

In the same area are farm vehicles and implements, including a number of steam traction engines once used on farms for threshing and harvesting and a thousand-and-one other duties.

In the automobile section there are many antique and classic exhibits, including a model of the now-renowned Stanley Steamer.

The museum excels however, in its still-growing railway collection which, at present, includes 10 steam locomotives, seven of which are in what can be described as a "hall of locomotives".

In this area four Canadian Pacific Railway locomotives share space with three from Canadian National Railways and its predecessors. CP Rail's units are led by number 3100, the giant 4-8-4 whose year-in, year-out duties, shared by sister number 3101, now preserved at Regina, Saskatcewan, was the hauling of the Montreal-Toronto night passenger trains, Numbers 21 and 22.

Cheek by jowl with number 3100 is H1d class 4-6-4 number 2858, one of the famed Royal Hudsons. There are facilities for visitors to enter and inspect the cabs of these once-active rail giants.

Further along the hall is G5a, 4-6-2, number 1201, the last locomotive built by Canadian Pacific at Angus Shops, Montreal, in 1944. Beside it is number 926, one of the 502 D10 class 4-6-0's which served the company faithfully for over half a century, from end to end of the system.

Other rolling stock at the museum includes Canada's oldest existing passenger coach, a car built in Montreal in 1859, for the old broad-gauge Grand Trunk line, two specially-built official cars which served Canada's governors-general from Lord Willingdon to General Georges Vanier, and an electric locomotive, line car, and other service equipment from London, Ontario.

In the related field of urban transportation, the museum houses two former horse-drawn streetcars, one from Toronto and one from Ottawa, each of which is approaching its centennial birthday, and one of Toronto's first electric streetcars. The collection from Toronto also includes a passenger sleigh and several antique buses.

Canadian Pacific is co-operating with the museum by making equipment available from time to time. Two of the most recent were superintendent's car number 23 and caboose number 435269, vintage 1905. Among smaller, portable items, is a truly magnificent collection of telecommunications instruments, sections of cable, documents, and souvenirs assembled over his career by T.J. "Phil" Laprade of CP Telecommunications, Ottawa. Other material of an historical or archival nature is earmarked for eventual donation.

The roster of aircraft is particularly complete and numbers more than seventy specimens, including a Fairchild 82 in early Canadian Pacific Airlines livery, one of the pioneer aircraft which played a leading role in opening the north. The collection is headed, chronologically, by the 1911 McDowell monoplane, the only one in Canada. During its flying days its speed was about 45 mph. There is also a Junkers J-1 "trench-strafer" from World War I, a recent-vintage RCAF Sabrejet, and other famous types.