These comments demonstrate that individuals who are untrained in patent law use the term novelty; when they sometimes mean originality. Modern patent law has a clear definition of novelty, whereas "originality" or "inventiveness" of an invention, called “inventive step” in European Patent Law, is considered separate.

The novelty of an invention is evaluated first because, for novelty, we essentially compare the invention's technical features with only one piece of prior art. Due to the fact that the examination of inventive step becomes obsolete in the absence of novelty, this easier assessment (=novelty) is performed first.

Accordingly an invention is only new if its technical features have not been made public prior to the filing date of the European patent application by means of a written or oral description, by use, or in any other manner." Novelty is absolute, ie. there are no limitations of any kind regarding the geographic area, language, age, or manner in which the relevant material was made available to the public. A written description, or document, is deemed to have been made available to the public if, as of the relevant date, it was feasible for members of the public to learn what was included within it and there was no bar of confidentiality preventing the use or distribution of such information. (Guidelines for the Examination of European Patents). As always, there may be other special circumstances that affect novelty. If you are in doubt it would be wise to consult a patent attorney.

The use of an exterior condenser to prevent heat losses is claimed to be the principal reason for the improved performance of the Watt steam engine. It is possible to determine if this observation is pertinent. The maximum piston's pressure while raising a column of water is reported for both Watt and Newcomen engines. A maximum of 14.75 psi, or the atmospheric pressure, may be pulled by an atmospheric engine's pistons. Atmospheric engines can counteract with their pistons a maximum pressure of 14.75 psi, which is the pressure of the atmosphere. Due to the steam engine's mechanical losses and the imperfect vacuum, this maximum value is actually lower in real-world applications. According to historical reports, the working cylinder within the Newcomen engine is typically cooled down to a temperature between 140 and 160 degrees Fahrenheit (60°C-71°C). The steam pressure of the steam still present in the cylinder at 152 degrees Fahrenheit (67°C) will be close to 4 psi. [30] The ratio of 4 psi to 14.75 psi, or around 27% of atmospheric pressure, is adopted in exchange for a shorter cycle time and avoiding further heat losses if the inside of the working cylinder would be cooled down to a lower temperature. In the same example, 52% of the maximum pressure (7.8 psi) [31] is ultimately used to raise water, with the remaining 18% going toward mechanical losses (friction, acceleration losses, etc.).

Watt steam engines use typically 68% of the maximum pressure for raising water. So we can see indeed an improvement of 15% of the Watt steam engine over the Newcomen steam engine to counter mechanical losses. A part of this improvement is likely due to the improved sealing of the piston. However, we also see that from a mechanical point of view the Newcomen steam engine was already at 52%, so that indeed the most radical improvement could be achieved only by an improvement of heat losses in the steam engine and the boiler.