Letter KNMI (Royal Dutch Meteorological Institute)
April 24, 2003

(Translation by Carl)




Date: April 24, 2003
Our reference: 03KD0549
Yor reference: none
Contact: R.J.C.F. Sluijter
Enclosures: 3


Concerns: Your letter April 14, 2003



Dear Mrs. v.d. Hoogen

In reply on your above mentioned letter I hereby inform you that the clouds as visible on the painting are of the type Cirrus and/or Cirrostratus.

Cirrus: Separate clouds, made of a soft tissue mostly with a silky glow, shadowless and usually white of color. Cirrus often appears like stripes or feathers. Often Cirrus is seen in bands in which Cirrostratus can be present also.

Cirrostratus: A thin whiteish fade which doesn't obscure the sun- or moonedges. Sometimes completely transparent resulting in a milky appearance of the sky. Cirrostratus often completely covers the entire sky.

Cirro/Cirrostratus belongs to the family of high clouds, usually they are found at a height of 5 to 10 km. The clouds are often (but not always) seen when fronts of low pressure systems are nearing.

I can not determine in any way whether the painting is painted on September 13th, 14th or 15th, 1883. The available weather data - which are in your possession already - in combination with the type of clouds doesn't exclude this either.

I can not determine whether a sunrise or sunset is seen, unfortunately there isn't any clue available.

I return you the foto's and wish you a lot of success with your further investigation.

Yours Sincerely,


drs. A.F.V. van Engelen
Head of the Climatological Service