July 7 is the nominal ‘birthday’ of this blog and I celebrate every year by posting a DIY star-themed project. This year I decided to share a planisphere.
In astronomy, a planisphere is a star chart analog computing instrument in the form of two adjustable disks that rotate on a common pivot. It can be adjusted to display the visible stars for any time and date. It is an instrument to assist in learning how to recognize stars and constellations.
The star map in the planisphere needs to be set for the latitude of the viewer and I found a lovely website that will generate a star chart for your location:
You can also download a kit to make one like the one below.
The star charts will work in the southern hemisphere as well, so although Matariki has passed this year —the first rising of the Pleiades star cluster— you can still use your planisphere to track the progress of The Seven Sisters across the southern sky.
I based the design of my holder on a planisphere produced commercially more than a century ago. (The image was uploaded to Pinterest by ‘Dorothea’ with no other information.)
If you wish make my version of the holder, you will need to print out the star wheel from this page. (The file is designed for A4 but will print on 8.5 x 11 inch card stock. Please do not adjust the size or your star wheel won’t match the holder.) Then download and print Planisphere Star Map Holder. I printed all my parts on lightweight card stock.
The front of the holder has been left plain. If you want to decorate it, do that before you begin cutting out the parts. I used both a knife and scissors for the cutting.
To make sure that the star wheel will slide easily inside the holder, the spacers —the small triangular shapes at the bottoms of both pages— need to be slightly thicker than the wheel. I cut a block of four and glued that to a scrap of copier paper. (Bottom left below. There are extra copies of the spacers in case you need to re-cut some to make everything fit.)
Cut out the wheel and the front and back of the holder along the outer black lines. When you cut the spacers I recommend cutting just inside the black line on the curve to ensure there is ease for the wheel to rotate smoothly when the planisphere is assembled.
The spacers will be glued to the outer corners of the inside back of the holder, matching the outer edges.
Test your fit before gluing. If things won’t stay in place for the test, use bulldog clips or clothespins to hold the spacers in place.
If everything fits properly, glue the spacers to the inside back and then glue the front corners to the spacers. (I put the glue on the spacers to make sure there isn’t any glue on the inside front or back that could stick to the star wheel.)
Operate your planisphere following the instructions from In-The-Sky.org (printed on the back). The wheel will rotate most easily if you hold the planisphere by a corner and grip the wheel in one of the spaces closest to that corner.
You can make your planisphere sturdier by making your star wheel twice as thick. Print and cut out your wheel, then glue it to a second sheet of card. Trim the second sheet to match the edges of the wheel. If you do this, you will also have to add a second layer of card stock to your corner spacers.
Have fun looking at the stars!
We have been under a “heat dome” this past week, experiencing record high temperatures so I tried an experiment. On the hottest day I made an ecoprint (resist method).
I left my bundle in a roasting pan in the hottest place in our yard for six hours. It only reached 125ºF —I checked with an oven thermometer— so there was no colour transfer from the leaves themselves, only from the Earl Grey and Rooibos teas I had sprinkled on the paper. The paper didn’t stay wet enough during the process and the bundle wasn’t tight enough to get clear resist prints all the way long, but it was fun to try.
I also made another seven squares for my #99DayProject. Here they are for those who haven’t been following on Instagram.
In other book arts news:
Online Delrin and Bamboo Toolmaking Workshops with Jeff Peachey!
Making tools is not only engaging and fun, but entirely practical since the result is set of tools you can use daily. Book conservators, other conservators, bookbinders, technicians, artists and others will find this workshop valuable. Filing, scraping and polishing are meditative activities, no previous experience required. Working Delrin and bamboo is a great way to start toolmaking and we will make folders, lifting tools, microspatulas, hera, and creasing tools. Most of the skills and techniques taught are transferable to wood and bone toolmaking too. Fair warning: making your own tools is highly addictive!
You can find the registration information here.
Timothy C. Ely’s recent blog post examines Richard Horton’s Book Sewings Workshop Guide. The post includes videos of some of the structures. You can find the review here.