The Adventures of Sherlock Holmes by Sir Arthur Conan Doyle

Hydraulic stamping machine / Hydraulic press

"'I say a night's work, but an hour's would be nearer the mark. I simply want your opinion about a hydraulic stamping machine which has got out of gear. If you show us what is wrong we shall soon set it right ourselves. What do you think of such a commission as that?'

(Adventure IX, pg. 122)

This we have now been doing for some time, and in order to help us in our operations we erected a hydraulic press.

(Adventure IX, pg. 123)

A huge hydraulic press designed by Stevenson that had lifted the metal tubes of a bridge at Bangor, was one of the exhibits in the Great Exhibition of 1851 in the Chrystal palace.

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Kettle

Then suddenly another sound became audible--a very gentle, soothing sound, like that of a small jet of steam escaping continually from a kettle.
(Adventure VIII, pg. 116)

Early kettles would have been made of iron and by the 19th century copper was a common material. In the mid 1900s alluminum and stainless steel kettles started to be manufactured.

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Bell pull

"Indeed, it seemed unnecessary to put so nice a bell-pull there. You will excuse me for a few minutes while I satisfy myself as to this floor."

(Adventure VIII, pg. 111)

The bell pull is one element of a complex interior mechanical network which typically in Victorian times involved a range of bell pulls in different rooms; moreover, these bell connections link to a central bank of bells in a room where servants would await commands.

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University medical degree

The last squire dragged out his existence there, living the horrible life of an aristocratic pauper; but his only son, my stepfather, seeing that he must adapt himself to the new conditions, obtained an advance from a relative, which enabled him to take a medical degree and went out to Calcutta, where, by his professional skill and his force of character, he established a large practice.
(Adventure VIII, pg. 103)

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1900s medical education system

Vitriol

There have been two murders, a vitriol-throwing, a suicide, and several robberies brought about for the sake of this forty-grain weight of crystallised charcoal.

(Adventure VII, pg. 92)

Vitriol, or sulfuric acid, was known since ancient times by islamic alchimists around 900 AD. In 1831, British vinegar merchant Peregrine Phillips patented the contact process, which was a far more economical process for producing sulfur trioxide and concentrated sulfuric acid. Today, nearly all of the world's sulfuric acid is produced using this method.

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Gas

These are the more patent facts which are to be deduced from his hat. Also, by the way, that it is extremely improbable that he has gas laid on in his house."

(Adventure VII, pg. 90)