VOL. XV.] PHILOSOPHICAL TRANSACTIONS. Ill 



horns, feelers, or brushes, consisting of 10 roundish joints, besides the first, 

 which is as long as two of the rest; they are all hairy, and like those of some 

 butterflies. BB the cowl or hat over the head, which appeared of a speckled 

 brown and yellowish colour, like tortoiseshell. CC the two eyes, composed 

 of innumerable small glassy hemispheres in rows, as has been observed by Mr. 

 Hook in his Micrography, to be the structure of insects' eyes, to supply their 

 defect of motion, by the number of their pupillae. DDDDDD the legs, of a 

 shelly fabric, like lobsters, and jointed in the same manner, covered with many 

 stiff hairs, though not so many as those of the blue-fly, represented by Mr. 

 Hook in his Micrograph, schem. 26. The mechanism of the feet are much " 

 the same, only what is there called the pattens were here wanting, if not broken 

 ofi^, and their use supplied by the gibbous part, ddd. The talons, eeeeee, of 

 the feet were shining, and very sharp-pointed. The legs consisted of two long 

 joints, and the feet of four more, besides that which was armed with the talons. 

 These seemed to be jointed into each other, and were all thick set with hairs or 

 bristles. E the thorax, consisting of but one shell, of a polished copper colour, 

 gtuck full of tapering bristles, with a small dent in the shell where each grew. 

 F the tail, consisting of 7 rings, of the same brownish colour, without hairs, 

 except on their edges, which were set with them like a thin fringe, as the tails 

 of lobsters, &c. are. These rings were of an unequal shining shell colour, f f 

 the back, or upper part of 2 or 3 rings of the tail, turned up to show the work 

 of the shell on that side. On the inside of the last of these was the light 

 placed, though there was now nothing to be seen except that part being a little 

 lighter coloured than the rest of the tail. GGG the membranous wings in 

 every particular like those of the blue fly, with hairs on the veins or quilly 

 parts. HH the insides of the case-wings, which were hairy, pointing all down- 

 wards. The outside of these cases was also very bristly. 



On the Wurtemhurg Siphon or Engine. By Mr. John Davis, Minister of Little 

 Leak, in Nottinghamshire. Translated from the Latin. N° 167, p. 846. 



This summer, l684, a treatise fell into my hands on the Wurtemhurg siphon, 

 which is an inverted one, with legs of equal height, running backward and 

 forward, in an uncommon manner. The author speaks in a wonderful manner 

 of this machine, but apologises to the reader for his most serene patron, who 

 wishes to reserve the structure of it to himself. On reading this, I considered 

 how a siphon might be constructed, which should perform the same things as 

 are ascribed to that of Wurtemhurg. Having therefore in my hands a certain 

 glass siphon, I erected it as nearly perpendicular as I could over two vessels; 



