How unusual was an unanswered naval salute of 150 guns?

Question

In naval tradition, ships and ports may expend gunpowder saluting each other, thus proving their respect and nonaggression. The respect so shown appears greater when more guns are shot off. A common pattern is that one party fires 7, 14, or 21 guns, which are answered equally by the other.

During Japan's period of isolation, the Dutch were restricted to the tiny island of Deshima and scrupulously deferent to their hosts. According to George Lensen's The Russian Push Toward Japan (pp. 148):

... the Dutch ships expected to leave their anchorage and, as was their custom, would salute the imperial fortress.... When the Dutch vessels duly departed from Deshima the following day, they saluted with a hundred and fifty guns each.... The Japanese did not return the salute.

150 guns with no response is very different from the other pattern, perhaps reflecting the unusual relationship those two powers were in. Did similarly disproportionate salutes happen anywhere else?

Answer 1

To answer your title question, a 150 gun salute would have been very unusual, not just because of the great number but because salutes were generally done with an odd number of guns.

1. The firing of gun salutes is a very old custom which appears to have originated in the early days of sail. Ships, when on goodwill visits to foreign ports, discharged all their guns to seaward on arrival thus indicating to the authorities ashore that their guns were empty and their visit peaceful.
2. Gun Salutes always consist of an odd number of rounds; the firing of an even number of rounds in olden days was always reserved for occasions of mourning. A salute is referred to as, for example, 'a salute of 21 guns' or a '21 gun salute' though nowadays only 2 or 3 guns actually fire the 21 charges.

^{Gun salutes - NMRN Portsmouth}

As time passed, the number of guns fired became more regimented and was determined by the relative status of the party receiving the salute. So for example, a ship carrying a foreign government envoy past a sovereign's castle might fire a 21-gun salute and receive a 5-gun salute in return. If the ship was carrying no one of any particular status then it may not expect any salute in return.

The exact number of guns fired would appear to vary by country and time period. The largest number formalised, according to wikipedia, appears to be the 101-gun salute reserved for "H.I.M The King-Emperor of India".

So an unanswered salute of 150 guns would have expressed an extreme imbalance of status between the two sides. The equivalent of kneeling with your forehead on the ground before a sovereign with them not visibly acknowledge that you're there.