Although the postcard itself says Praça da Liberdade, the photo was likely made before the 1910 revolution changing Portugal from a monarchy into a republic. All trams of the photo are of pre-1910 types. In the foreground is 124, a former mule tram. In the background are 123 and another, maybe 118. At the left is the Palácio das Cardosas, in the background the Rua dos Clerigos with the church and tower of that name.
On Praça are the trams 151, build in 1904 by the local company A Constructora, and 124, an electrified former mule tram. Behind these two trams are two other trams. At the right is one of the two open trams 141-142, likely 142, converted in 1904 by A Constructora from a mule tram to an electric tram.
At the left is the Palácio das Cardosas, at the right the Igeja dos Congrelados. In the background is the Rua dos Clerigos with the church and tower of that name.
This postcard shows tram 18 on Praça Dom Pedro IV and two other trams, the first likely 10, in Rua dos Clerigos.
Although the postcard says Praça da Liberdade, which means it was printed after 1910, the photo is from quit some years before. The tram at the left has the number 36. The fleet numbers of the trams were raised in 1907 by hundred. Photos showing a Porto electric tram with a number below 100 are not taken later as 1907. Tram 36 was in 1902 converted from a mule tram to an electric tram, which means 1903 is the earliest year this photo can be taken.
The number of the tram at the right is alas hidden by a lady with a basket on her head. This tram has a BSI truck and might be one of the three trams build new in 1898/9 by the workshops or a former mule tram / steam tram trailer converted to electric tram about the same period. At the left is the Palácio das Cardosas and in the background the Rua dos Clerigos with the church and tower of that name.
This stereo photo shows tramcar 46 with in the background one of the two open trams 41-42. Tramcar 46 was build in 1904 by the local company A Constructora and in 1906/7 reconstructed by the workshops into a 7-window car getting the number 201. The trams 41 and 42 were in 1904 converted by A Constructora from mule trams to electric trams. The photo is taken on Praça Dom Pedro IV, since 1910 Praça da Libedade.