·         “The inventions of IR #2 were so important…that they took a full 100 years to have their main effect.” ·         “…[T]he productivity impact of IR #3 evaporated after only eight years, compared to the 81 years (1891-1972) required for the benefits of IR #2 to have their full impact…”
·         "وعلى أقل تقدير، استغرق الأمر 150 عاماً قبل أن تخلف الثورة الصناعية الأولى النطاق الكامل لتأثيراتها".