EECEEATIVE SCIENCE. 



275 



die of each of the following lines, a B, B c, 

 c a, A E, H G, and H E. If he will then con- 

 nect these points by lines passing along the 

 faces of the cube, he will delineate, in per- 

 spective, a regular hexagon. This he can 

 show by cutting a cube of soap in a cor- 

 responding manner. It is most desirable that 

 the student in geometry, or in isometrical 

 perspective, as well as the artificer who has 

 to deal with the conversion of materials, 

 should have an accurate conception of these 

 several sections of the cube, and he should, 

 therefore, adopt every mode of illustrating 

 them. One of the most desirable plans is to 

 draw the lines of the sections on the envelope 

 of a cube, as shown in Fig 9, where the 

 double lines represent the section through two 

 faces ; the single diagonal lines show one of 

 the largest sections through three faces ; the 



fine dotted lines the rhombic section through 

 four faces ; and the coarser dotted lines the 

 hexagonal section through all the faces. The 

 student is strongly recommended to draw 

 these several sections on separate envelopes 

 of cubes, so that, when each is folded up, tho 

 position of the sections shall be evident. 



Having now gone through a few of tho 

 properties, and some of the more interesting 

 sections of the cube, and having exhausted 

 the space devoted to the subject, we must 

 necessarily defer the consideration of the 

 beautiful solid forms which are contained 

 within it, to our next paper on the subject, 

 concluding our remarks by strongly recom- 

 mending our readers to follow the descrip- 

 tions, by the aid of the simple appliances in- 

 dicated in this paper. 



W. B. TegetMeieb. 



THE ELECTEOTYPE. 



Unwieldy as is the apparatus used by the 

 professional electrotypist, and numerous as 

 are the articles which he has occasionally to 

 employ, it is nevertheless quite possible to 

 make many very interesting experiments as 

 a means of recreation, and to produce objects 

 of ornament and utility, by the aid of appa- 

 ratus of the most simple and inexpensive 

 character. 



Knowing, as we do, that many are de- 

 terred from attempting the practice of this 

 interesting art, by the idea that its processes 

 are costly, uncertain, and difficult, it has oc- 

 curred to us that an accoixnt of some experi- 

 ments which we have lately had occasion to 

 make with apparatus of the very simplest 

 kind, would not be unacceptable to those 

 who find their recreation in the pursuits of 

 science. Our special object was to reproduce 

 fac-similes of a series of coins ; but as the 

 descriptioa of the process employed upon one 



equally serves for all, we will confine our 

 attention to one coin only, and, for the sake 

 of our readers, we will speak of a coin acces- 

 sible to all, rather than some rare one, which 

 possibly they may have never seen. 



Let us suppose, then, that we have before 

 us a florin — it would be well to select one 

 that is not too much abraded or worn — and 

 that we wish to produce a fac-simile of the 

 side containing the royal profile in copper. 

 The first thing to be done is to prepare a 

 mould, that is, a counterpart, in lead,* of the 

 coin to be copied. To do this, take any small 

 vessel of earthenware, as a tea-cup, and press 

 a piece of writing-paper into the bottom, so 

 as to form a kind of rough lining to the vessel. 



* Better than lead would be the metal called 

 fusible alloy, which may be made by mixing intimately 

 8 oz. of bismuth, 5 oz. of lead, and 3 oz. of tin. This 

 alloy melts readily at a temperature rather lower than 

 that of boiUag water. It may be purchased ready 

 prepared. 



