THE ESSEX FIELD CLUB. 4 1 



of the whole exposure, so that solid objects were seen through the figure in the 

 resuhing print. 



In astronomical photography, Professor Meldola stated, dry plates are par- 

 ticularly useful, and they are now being employed for an international survey of 

 the heavens. He here exhibited two fine slides by Mr. Isaac Roberts, a pioneer 

 in such work. The one photograph represeited a nebula in the constellation of 

 the Little Dog, and the other the Great Nebula in Orion. In these, he pointed 

 out, were also great numbers of stars, and among them some invisible to the 

 human eye, except by the aid of photography. Photography has also revealed 

 the fact that some objects, hitherto classed as stars, and mapped as such, are in 

 reality small nebulas. These photographs had been taken with a reflector, and 

 not with a lens, with an exposure of four hours, and by using most delicate 

 appliances to enable the telescope to follow accurately the apparent motions of 

 the heavenly bodies without vibration. The exposure given in taking each of 

 the nebulas was four hours. An American astronomer onre spent many years in 

 drawing the Great Nebula in Orion. He next exhibited another photograph, by Mr. 

 Roberts, of a beautiful nebula in Andromeda, which also was taken with a reflector. 



Photography might also be used for securing records of natural phenomena. 

 He projected on the screen two slides, representing the river at Wakefield in its 

 ordinary condition, and during the flood of 1892. These, and some other slides, 

 belonged to a committee of the British Association, which is collecting photo- 

 graphs of meteorological phenomena ; the slides had been lent to him by Mr. 

 Symons. He exhibited also frost and snow scenes, and said that recently some 

 beautiful photographs of snow crystals have been taken on the Continent. Whe.i 

 dealing with cloud photography he described Mr. Clayden's work, and projected 

 specimens on the screen. He also exhibited a striking photograph of the Malvern 

 Hills, the crests only projecting above the mist, which latter seemed rolling 

 onwards like a great sea. Photographs of lightning flashes were then exhibiteJ, 

 one by Mr. Frank Hughes, showing that flashes are not always single, and that 

 several flashes may occur from different parts of a cloud at the same time. He 

 said that lightning flashes are sometimes double, and that separate images are 

 sometimes obtained by moving the camera while the electrical discharge takes 

 place. 



Another Committee of the British Association is now using photography in 

 making an ethnographic survey by Mr. Francis Galton's method, to a Id to the 

 stock of information about race characteristic Photography is also used in aid 

 of archaeologv, and sometimes to give evidence relating to disputed points. P'or 

 instance, various prehistoric temples are supposed to be "oriented," so that the 

 chief altar directly faces the rising sun on the longest day — the summer solst'cc. 

 The lecturer exhibited a slide of the rising sun at Stonehenge on the longest 

 day of the year, taken from what is assumed to have been the most sacred 

 part. The sun then appeared on the apex of a huge stone, called the Friar's Heel, 

 and chanced on that particular morning to be surrounded by a halo, so as to make 

 a striking picture, seen through the "bridge," if so it may be called, formed 

 by two perpendicular stones in the foreground, between them supporting one huge 

 stone on the top. The lecturer next spoke of the way in which photography is being 

 utilised by the Geological Photographs Committee of the British Association, 

 and showed some slides lent by the Secretary to the Committee, Mr. Jeffs, repre- 

 senting inland erosion by wind and water, the erosion of sea coasts, the formation 

 of caverns, the nature of basaltic formations, and the records of glacial action in 

 former times pres'-rved by certain rocks. He exhibited a photograph of part of 



