Architecture.- Heating.- Engel (Carl Ludwig) Richtige Anweisung zur Heitzung der Gebäude mit erwärmter, first edition, rare, Berlin, [A. Petsch], 1830.

Architecture.- Heating.- Engel (Carl Ludwig) Richtige Anweisung zur Heitzung der Gebäude mit erwärmter, first edition, 3 folding engraved plates, water-stained, occasional spotting, contemporary marbled boards, spine gilt and with orange leather label, rubbed, 4to, Berlin, [A. Petsch], in der Stuhr'schen Buchhandlung, 1830.

⁂ Rare work on the heating of buildings. The German architect Engel was responsible for most of Helsinki's key buildings, including The Senate, Helsinki Cathedral, the library and parts of the university.