3 2 



HARD WICKE'S S CIENCE- G OS SIP. 



formed a decumbent stem about a foot in length, 

 producing leaves 15 to 16 feet long. 



Dr. Berthold Seemann, also a botanical collector for 

 Kew, found the Phytelephas in abundance in Darien ; 

 he gives a very interesting account of it, which in all 

 principal points agrees with the above. 



J. Sm. 



HINTS FOR THE YOUNG MICROSCOPIST. 



IT has often occurred to the writer of these few 

 lines that it is a pity that so many practical 

 dodges as must have been adopted by various micro- 

 scopical manipulators should be lost, as it is to be 

 feared they have been from time to time. Unless 

 called out by queries, they seldom appear in the form 

 of suggestions. Acting under this impression, the 

 writer is led to call attention to two or three little 

 arrangements which he has found very useful, hoping 

 that others will follow the example. 



Fig. 30. — Brass stand to 

 support the forehead 

 whilst making micro- 

 scopical drawings. 



Fig. 31. — Improved wash- 

 bottle. 



In making drawings of objects seen under the 

 microscope (for which purpose no apparatus is so 

 satisfactory and easy to use as Natchet's prism or 

 camera), most persons must be conscious that a steady 

 head is as requisite as a steady hand. To insure this, 

 a very simple plan (fig. 30) has been adopted for a 

 long time by the writer. It is this : — two thin stair- 

 rods (a, a) of any convenient length are fastened by 

 one end into a stand of brass or wood (b), and just as 

 far apart as to admit the head between them. Then 

 there is a sliding flat bar (c), which can be screwed 

 tight at any height. Round this is wrapped any soft 

 substance, as lint or list, on which the forehead is 

 placed just in the position desired. A steadiness and 

 comfort are thus at once obtained which greatly assist 

 the draughtsman. 



Again, in using the wash-bottle the following little 

 alteration will be found most convenient. (Fig. 31.) 

 In place of having two glass tubes, one of which is 

 placed in the mouth, let this mouth-tube be broken 

 off an inch or two above the cork, and upon it fit an 

 elastic indiarubber tube (a) of any convenient length, 



say nine inches ; then a couple of inches of glass tube 

 put into the free end (b) makes a nice mouthpiece. 

 The advantage is obvious, as this plan allows the head 

 to be moved nearer to or farther from the object 

 without interfering with the position of the bottle. 

 This has been used by the writer for many years. 



Other suggestions may follow if it is thought 

 desirable. 



Codicote Vicarage. T. R. I. 



THE BOULDER CLAY OF LEITH. 



IT may interest your readers to learn something 

 regarding the traces that have been left of the 

 glacial period in this vicinity, which has proved to 

 be a very interesting one in regard to that part of 

 geological history. 



Edinburgh is surrounded by an extent of country 

 covered, more or less, with a thick layer of boulder 

 clay. In most of the excavations in and around the 

 city, this is reached after passing through the soil 

 to an average depth of six to seven feet. To the 

 south of the city, away on the first slopes rising 

 towards the Pentland hills, the boulder clay is very 

 thick, and forms a fine basin for the new reservoir in 

 course of construction at Alnwick hill. From that 

 point we can trace the clay to the north, through the 

 Newington district of the town, where I have found it 

 with the usual striated boulders. Passing through 

 the city this deposit disappears on reaching the ridge 

 which goes upwards towards the castle, till we 

 approach Leith Walk, where it is again found. Some 

 cuttings at Pilrig — the border-land between Edin- 

 burgh and Leith — have revealed the boulder-clay 

 about seven feet from the surface. It is not, however, 

 till we examine the shore at Leith that we get any- 

 thing like a good section of it ; and here both the 

 mercantile enterprise of that town and the denuding 

 power of the ocean, have come to our aid. As a 

 result of the latter, the banks which rise against the 

 sea between Leith and Portobello, are gradually 

 giving way and receding, revealing the tough boulder 

 clay, which seems to die hard in its battle with the 

 sea. 



When the boulders are found in situ, they are 

 almost invariably lying with their longer axis from 

 W. S. W. to E. N. E., and are striated in the same 

 direction. This agrees with the strise in Arthur's 

 Seat, a hill rising to the east of Edinburgh and 

 about two miles from the coast. I have found those 

 boulders all along the coast from Cramond to Joppa, 

 a distance of nine miles, but they are best seen 

 between Leith and Portobello, where they lie thickly 

 and where many of them have beautifully marked 

 striae. The ground here has been rendered geologi- 

 cally classic by the writings of Dr. Robert Chambers 

 and Hugh Miller ; the former however, attributing 

 the phenomena in question to the agency of the sea 



